Added(A)/Deleted(D) following books

 D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_7.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_1.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_2.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_3.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_4.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_5.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_6.ipynb
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_7.ipynb
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D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter32example30_4.png
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter32example30_5.png
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter32example30_6.png
D  A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter32example30_7.png
A  Introduction_to_Power_Electronics_by_V._Jagannathan/chapter2.ipynb
A  Introduction_to_Power_Electronics_by_V._Jagannathan/chapter3.ipynb
A  Introduction_to_Power_Electronics_by_V._Jagannathan/chapter4.ipynb
A  Introduction_to_Power_Electronics_by_V._Jagannathan/chapter5.ipynb
A  Introduction_to_Power_Electronics_by_V._Jagannathan/chapter7.ipynb
A  Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/avgArmCurr7_.png
A  Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/speedmotor7.png
A  Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/triggeringangle7.png
A  "sample_notebooks/ArchanaDharmasagar Kalidas/Chapter1.ipynb"

153 files changed, 2864 insertions, 199512 deletions

diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_1.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_1.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_2.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_2.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_3.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_3.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_4.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_4.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_5.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_5.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_6.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_6.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_7.ipynb
deleted file mode 100755
index 884c7e96..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter25_7.ipynb
+++ /dev/null
@@ -1,173 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0a9697b2451ba5bc5f24eb67c66ef466539d8d3c214c7c35bb64d3c339daf3f9"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 25: Elements of Electro-Mechanical Energy Conversion"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.1, Page Number:876"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "sod=15#stator-core outer diameter\n",
-      "sid=10.05#stator-core inner diameter\n",
-      "rod=10.00#rotor-core outer diameter\n",
-      "rid=5#rotor-core inner diameter\n",
-      "a=8#axial lenght of the machine\n",
-      "b=1.20\n",
-      "ur=1000\n",
-      "#calculations\n",
-      "vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
-      "vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
-      "va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
-      "ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
-      "e=ed*va*math.pow(10,-6)\n",
-      "edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
-      "es=edm*vs*math.pow(10,-6)\n",
-      "er=edm*vr*math.pow(10,-6)\n",
-      "kr=(vs+vr)/vs\n",
-      "ke=(es+er)/e\n",
-      "ratio=kr/ke\n",
-      "eratio=e/(es+er)\n",
-      "\n",
-      "#result\n",
-      "print \"Energy stored in air gap= \",e,\" Joules\"\n",
-      "print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
-      "print \"Energy stored in rotor core= \",er,\" Joules\"\n",
-      "print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Energy stored in air gap=  3.609  Joules\n",
-        "Energy stored in stator-core=  0.45  Joules\n",
-        "Energy stored in rotor core=  0.27  Joules\n",
-        "Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.2, Page Number:877"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "n=800#turns\n",
-      "area=5*5#cross sectional area\n",
-      "i=1.25#amp\n",
-      "x=0.25#cm\n",
-      "l=0.402\n",
-      "#calculations\n",
-      "p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
-      "l=n**2*p\n",
-      "em=.5*i*i*l\n",
-      "W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)coil inductance=\",l,\"H\"\n",
-      "print \"  ii)field energy stored=\",em,\"J\"\n",
-      "print \"b)mechanical energy output=\",W,\"NW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)coil inductance= 0.40192 H\n",
-        "  ii)field energy stored= 0.314 J\n",
-        "b)mechanical energy output= -62.8 NW\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 25.4, Page Number:882"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "lo=50#mH\n",
-      "xo=0.05#cm\n",
-      "r=0.5#ohm\n",
-      "x=0.075#cm\n",
-      "i2=3#A\n",
-      "x2=0.15#cm\n",
-      "\n",
-      "#calculation\n",
-      "l1=2*lo/(1+(x/xo))\n",
-      "lambda1=l1*i2*10**(-3)\n",
-      "W=0.5*l1*i2**2*10**(-3)\n",
-      "l2=2*lo/(1+(x2/xo))\n",
-      "lambda2=l2*i2*10**(-3)\n",
-      "w2=0.5*i2*(lambda1-lambda2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)magnetic stored energy=\",W,\"J\"\n",
-      "print \"b)change in magnetic stored energy=\",w2,\"J\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)magnetic stored energy= 0.18 J\n",
-        "b)change in magnetic stored energy= 0.0675 J\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_1.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_1.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_2.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_2.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_3.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_3.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_4.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_4.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_5.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_5.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_6.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_6.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_7.ipynb
deleted file mode 100755
index 1af9bb80..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter26_7.ipynb
+++ /dev/null
@@ -1,1600 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:fbc29937443ef7eae8e50df5118b16ddcc8ed6efb4b30db1cb412240bf7eac02"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 26: D.C. Generators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.3, Page Number:912"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=450#A\n",
-      "v=230#v\n",
-      "rs=50#ohm\n",
-      "ra=.03#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "va=ia*ra\n",
-      "E=v+va\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f. generated in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f. generated in the armature=  243.62  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.4, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=500#v\n",
-      "rs=250#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.03#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "vs=ia*rseries\n",
-      "va=ia*ra\n",
-      "vb=ish*b\n",
-      "E=v+va+vs+vb\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  506.16  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.5, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=30#A\n",
-      "v=220#v\n",
-      "rs=200#ohm\n",
-      "ra=.05#ohm\n",
-      "rseries=0.30#ohm\n",
-      "b=1#V\n",
-      "\n",
-      "#calculations\n",
-      "vs=i*rseries\n",
-      "vshunt=v+vs\n",
-      "ish=vshunt/v\n",
-      "ia=i+ish\n",
-      "vb=b*2\n",
-      "E=v+vs+vb+(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"generated voltage in the armature= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "generated voltage in the armature=  232.552045455  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.6, Page Number:913"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": true,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#v\n",
-      "i=150.0#A\n",
-      "rs=92.0#ohm\n",
-      "rseries=0.015#ohm\n",
-      "rd=0.03#ohm(divertor)\n",
-      "ra=0.032#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rs\n",
-      "ia=i+ish\n",
-      "sdr=(rd*rseries)/(rd+rseries)\n",
-      "tr=ra+sdr\n",
-      "vd=ia*tr\n",
-      "Eg=v+vd\n",
-      "tp=Eg*ia\n",
-      "pl=(ia*ia*ra)+(ia*ia*sdr)+(v*ish)+(v*i)\n",
-      "\n",
-      "#resuts\n",
-      "print \"i) Induced e.m.f.= \",Eg,\" V\"\n",
-      "print \"ii)Total power generated= \",tp,\" W\"\n",
-      "print \"iii)Distribution of the total power:\"\n",
-      "print \" power lost in armature=                \", ia*ia*ra\n",
-      "print \"power lost in series field and divider= \", ia*ia*sdr\n",
-      "print \"power dissipated in shunt winding=      \", v*ish\n",
-      "print \"power delivered to load=                \", v*i\n",
-      "print \"                                         ------------\"\n",
-      "print \"Total=                                  \", pl"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) Induced e.m.f.=  236.405  V\n",
-        "ii)Total power generated=  36051.7625  W\n",
-        "iii)Distribution of the total power:\n",
-        " power lost in armature=                 744.2\n",
-        "power lost in series field and divider=  232.5625\n",
-        "power dissipated in shunt winding=       575.0\n",
-        "power delivered to load=                 34500.0\n",
-        "                                         ------------\n",
-        "Total=                                   36051.7625\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.7, Page Number:914"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=300000.0#w\n",
-      "v=600.0#v\n",
-      "sr=75.0#ohm\n",
-      "abr=0.03#ohm\n",
-      "cr=0.011#ohm\n",
-      "rseries=0.012#ohm\n",
-      "dr=0.036#ohm\n",
-      "\n",
-      "#calculatons\n",
-      "io=p/v#output current\n",
-      "ish=v/sr\n",
-      "ia=io+ish\n",
-      "sdr=(rseries*dr)/(rseries+dr)\n",
-      "tr=abr+cr+sdr\n",
-      "vd=ia*tr\n",
-      "va=v+vd\n",
-      "pg=va*ia\n",
-      "W=pg/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generatedby the armature= \",va,\" V\"\n",
-      "print \"Power generated by the armature= \",W, \"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generatedby the armature=  625.4  V\n",
-        "Power generated by the armature=  317.7032 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.8, Page Number:915"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "phi=7*math.pow(10,-3)\n",
-      "z=51*20\n",
-      "a=p=4\n",
-      "n=1500#r.p.m\n",
-      "\n",
-      "#calculations\n",
-      "Eg=(phi*z*n*p)/(a*60)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage generated= \",Eg,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage generated=  178.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.9, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=8\n",
-      "phi=0.05#Wb\n",
-      "n=1200#rpm\n",
-      "N=500#armature conductor\n",
-      "\n",
-      "#calculations\n",
-      "E=phi*(n/60)*(p/a)*N\n",
-      "\n",
-      "#result\n",
-      "print \"e.m.f generated= \",E,\" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e.m.f generated=  500.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.10, Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=127#v\n",
-      "vt=120#v(terminal voltage)\n",
-      "r=15#ohms\n",
-      "i1=8.47#A\n",
-      "ra=0.02#ohms\n",
-      "fi=8#A\n",
-      "\n",
-      "#calculations\n",
-      "Eg=v+(i1*ra)\n",
-      "ia=(Eg-vt)/ra\n",
-      "il=ia-fi\n",
-      "\n",
-      "#result\n",
-      "print \"Load current \",il,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current  350.47  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(a), Page Number:917"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=778\n",
-      "n=500\n",
-      "ra=0.24\n",
-      "rl=12.5\n",
-      "r=250\n",
-      "v=250\n",
-      "a=2\n",
-      "#calculations\n",
-      "il=v/rl\n",
-      "si=v/r\n",
-      "ai=il+si\n",
-      "emf=v+(ai*ra)\n",
-      "phi=(emf*60*a)/(p*z*n)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ai,\" A\"\n",
-      "print \"induced e.m.f.= \",emf,\" V\"\n",
-      "print \"flux per pole= \",round(phi*1000,2),\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  21.0  A\n",
-        "induced e.m.f.=  255.04  V\n",
-        "flux per pole=  9.83  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.11(b), Page Number:916"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "P=5000.0#w\n",
-      "P2=2500.0#W\n",
-      "v=250.0#v\n",
-      "ra=0.2#ohm\n",
-      "r=250.0#ohm\n",
-      "z=120\n",
-      "N=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "gc=P/v\n",
-      "li=P2/v\n",
-      "ti=gc+li\n",
-      "fc=1\n",
-      "ai=ti+fc\n",
-      "ard=ai*ra\n",
-      "emf=v+ard+2\n",
-      "phi=(emf*60*a)/(p*z*N)\n",
-      "ac_perparralelpath=ai/p\n",
-      "\n",
-      "#result\n",
-      "print \"Flux per pole= \",phi*1000,\" mWb\"\n",
-      "print \"Armature current per parallel path= \",ac_perparralelpath,\" A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Flux per pole=  129.1  mWb\n",
-        "Armature current per parallel path=  7.75  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.12, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=125.0#V\n",
-      "n1=1000#rpm\n",
-      "n2=800#rpm\n",
-      "ra=0.04#ohm\n",
-      "bd=2.0#V(brush drop)\n",
-      "\n",
-      "#calculations\n",
-      "R=v/i\n",
-      "E1=v+(i*ra)+bd\n",
-      "E2=(E1*n2)/n1\n",
-      "il=(E2-bd)/0.675\n",
-      "\n",
-      "#result\n",
-      "print \"Load current when speed drops to 800 r.p.m.= \",round(il,2),\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load current when speed drops to 800 r.p.m.=  157.04  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.13, Page Number:918"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "n=900 #rpm\n",
-      "V=220#V\n",
-      "E=240#V\n",
-      "ra=0.2#ohm\n",
-      "phi=10#mWb\n",
-      "N=8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(E-V)/ra\n",
-      "Z=(E*600*2)/(phi*math.pow(10,-3)*n*p)\n",
-      "#since there ae 8 turns in a coil,it means there are 16 active conductor\n",
-      "number_of_coils=Z/16\n",
-      "\n",
-      "#result\n",
-      "print \"armature current= \",ia,\" A\"\n",
-      "print \"number of coils= \",number_of_coils"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current=  100.0  A\n",
-        "number of coils=  500.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.14, Page Number:919"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=120.0#V\n",
-      "ra=0.06#ohm\n",
-      "rs=25#ohm\n",
-      "rsw=0.04#ohm(series winding)\n",
-      "il=100.0#A\n",
-      "#i)Long shunt\n",
-      "ish=V/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to long shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to long shunt=\",ia,\" A\"\n",
-      "\n",
-      "#i)Short shunt\n",
-      "vds=il*rsw\n",
-      "vs=V+vds\n",
-      "ish=vs/rs\n",
-      "ia=il+ish\n",
-      "vd=ia*rsw\n",
-      "vda=ia*ra\n",
-      "E=V+vd+vda\n",
-      "\n",
-      "print \"Induced e.m.f. when the machine is connected to short shunt= \",E,\" V\"\n",
-      "print \"Armature current when the machine is connected to short shunt=\",ia,\" A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Induced e.m.f. when the machine is connected to long shunt=  130.48  V\n",
-        "Armature current when the machine is connected to long shunt= 104.8  A\n",
-        "Induced e.m.f. when the machine is connected to short shunt=  130.496  V\n",
-        "Armature current when the machine is connected to short shunt= 104.96  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.15, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=25000.0#W\n",
-      "V=500.0#V\n",
-      "ra=0.03#ohm\n",
-      "rs=200.0#ohm\n",
-      "rseries=0.04#ohm\n",
-      "vb=1.0#V\n",
-      "n=1200#rpm\n",
-      "phi=0.02#Wb\n",
-      "\n",
-      "#calculations\n",
-      "i=p/V\n",
-      "ish=V/rs\n",
-      "ia=i+ish\n",
-      "p=4\n",
-      "vds=ia*rseries\n",
-      "vda=ia*ra\n",
-      "vdb=vb*2\n",
-      "E=V+vds+vda+vdb\n",
-      "Z=(E*60*4)/(phi*n*p)\n",
-      "\n",
-      "#result\n",
-      "print \"The e.m.f. generated= \",E,\" V\"\n",
-      "print \"The number of conductors=\",Z"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "The e.m.f. generated=  505.675  V\n",
-        "The number of conductors= 1264.1875\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.16, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=750#rpm\n",
-      "e=240.0#V\n",
-      "z=792\n",
-      "phi=0.0145#Wb\n",
-      "\n",
-      "#calculations\n",
-      "phi_working=(e*60*2)/(n*z*p)\n",
-      "lambda_=phi/phi_working\n",
-      "\n",
-      "#results\n",
-      "print \"Leakage coefficient= \",round(lambda_,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Leakage coefficient=  1.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.17, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rt=0.004#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "rtotal=t*rt\n",
-      "r_eachpath=rtotal/p\n",
-      "ra=r_eachpath/a\n",
-      "vda=ia*ra\n",
-      "V=E-vda\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal Voltage= \",V, \" V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal Voltage=  459.25  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.18, Page Number:920"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "phi=0.07#Wb\n",
-      "t=220\n",
-      "rturn=0.004#ohm\n",
-      "rs=100.0#ohm\n",
-      "rsc=0.02#ohm\n",
-      "n=900#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "z=2*t\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ra=0.055#ohm\n",
-      "ra=ra+rsc\n",
-      "va=ia*ra\n",
-      "v=E-va\n",
-      "ish=v/rs\n",
-      "i=ia-ish\n",
-      "output=v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Output= \",round(output/1000,3),\" kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output=  20.813  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.19, Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=1200#rpm\n",
-      "ia=200#A\n",
-      "v=125#V\n",
-      "n2=1000#rpm\n",
-      "ra=0.04#ohm\n",
-      "vb=2#V\n",
-      "\n",
-      "#calculations\n",
-      "E1=v+vb+(ia*ra)\n",
-      "E2=E1*n2/n1*0.8\n",
-      "\n",
-      "#results\n",
-      "print \"Generated e.m.f. when field current is reduced to 80%=\",E2,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Generated e.m.f. when field current is reduced to 80%= 90.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(a), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "rs=100.0#ohm\n",
-      "ra=1.0#ohm\n",
-      "z=378\n",
-      "phi=0.02#Wb\n",
-      "rl=10.0#ohm\n",
-      "n=1000#rpm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "V=(100.0/111.0)*E\n",
-      "il=V/rl\n",
-      "P=il*V\n",
-      "\n",
-      "#result\n",
-      "print \"Power absorbed by the load is= \",P,\" W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power absorbed by the load is=  5154.12710007  W\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.20(b), Page Number:921"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=300\n",
-      "phi=0.1#Wb\n",
-      "n=1000#rpm\n",
-      "ra=0.2#rpm\n",
-      "rf=125#ohm\n",
-      "il=90#A\n",
-      "\n",
-      "#calculations\n",
-      "E=(phi*z*n*p)/(60*a)\n",
-      "ifield=E/rf\n",
-      "ia=ifield+il\n",
-      "V=E-(ia*ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Terminal voltage= \",V,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Terminal voltage=  481.2  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(a), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "n=1200#rpm\n",
-      "e=250.0#V\n",
-      "d=350.0#mm\n",
-      "air_gap=3.0#mm\n",
-      "al=260.0#mm\n",
-      "fringing=0.8\n",
-      "coils=96\n",
-      "t=3\n",
-      "\n",
-      "#calculations\n",
-      "z=t*coils*2\n",
-      "a=p*2\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "di=d+air_gap\n",
-      "pole_arc=(3.14*di*fringing)/6\n",
-      "B=phi/(pole_arc*0.000001*al)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi,\" Wb\"\n",
-      "print \"effective pole arc lenght= \",pole_arc*0.001,\" m\"\n",
-      "print \"flux density= \",B,\" T\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  0.0434027777778  Wb\n",
-        "effective pole arc lenght=  0.147789333333  m\n",
-        "flux density=  1.12953862717  T\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(b), Page Number:922"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=1200\n",
-      "e=250.0#v\n",
-      "n=500#rpm\n",
-      "b=35.0#cm\n",
-      "ratio=0.7\n",
-      "lpole=20.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "pole_pitch=(b*3.14)/p\n",
-      "polearc=ratio*pole_pitch\n",
-      "pole_area=polearc*lpole\n",
-      "phi=(e*60*a)/(n*z*p)\n",
-      "mean_flux=phi/(pole_area*math.pow(10,-4))\n",
-      "              \n",
-      "#result\n",
-      "print \"Mean flux density= \",mean_flux,\" Wb/m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Mean flux density=  0.649941505265  Wb/m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.21(d), Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=100.0#V\n",
-      "ra=0.04#ohm\n",
-      "rseries=0.03#ohm\n",
-      "rs=60.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v+(i*rseries)\n",
-      "ish=va/rs\n",
-      "ia=i+ish\n",
-      "e=va+(ia*ra)\n",
-      "\n",
-      "#long shunt\n",
-      "ishunt=v/rs\n",
-      "vd=ia*(ra+rseries)\n",
-      "e2=v+vd\n",
-      "\n",
-      "#result\n",
-      "print \"emf generated(short shunt)\",e,\" V\"\n",
-      "print \"emf generated(long shunt)\",e2,\" V\"\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf generated(short shunt) 114.070666667  V\n",
-        "emf generated(long shunt) 114.123666667  V\n",
-        "\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.22, Page Number:923"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "w=20000.0#W\n",
-      "v=220.0#v\n",
-      "ra=0.04#ohm\n",
-      "rs=110.0#ohm\n",
-      "rseries=0.05#ohm\n",
-      "efficiency=.85\n",
-      "\n",
-      "#calculations\n",
-      "il=w/v\n",
-      "i_f=v/rs\n",
-      "ia=il+i_f\n",
-      "ip=w/efficiency#input power\n",
-      "total_loss=ip-w\n",
-      "copper_loss=(ia*ia*(ra+rseries))+(i_f*i_f*rs)\n",
-      "ironloss=total_loss-copper_loss\n",
-      "omega=2*3.14*n/60\n",
-      "T=ip/omega\n",
-      "\n",
-      "#omega\n",
-      "print \"Copper loss= \",copper_loss,\" W\"\n",
-      "print \"Iron and friction loss= \",ironloss,\" W\"\n",
-      "print \"Torque developed by the prime mover= \",T,\"Nw-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Copper loss=  1216.88892562  W\n",
-        "Iron and friction loss=  2312.52283909  W\n",
-        "Torque developed by the prime mover=  224.803297115 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.23, Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declartaion\n",
-      "power=10000.0#W\n",
-      "v=250.0#V\n",
-      "p=a=6\n",
-      "n=1000.0#rpm\n",
-      "z=534\n",
-      "cu_loss=0.64*1000#W\n",
-      "vbd=1.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=power/v\n",
-      "ra=cu_loss/(ia*ia)\n",
-      "E=v+(ia*ra)+vbd\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole= \",phi*1000,\" mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole=  30.0  mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(a), Page Number:928"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=195#A\n",
-      "pd=250#V\n",
-      "ra=0.02#ohm\n",
-      "rsh=50#ohm\n",
-      "p=250#W\n",
-      "strayloss=950#W\n",
-      "#calculations\n",
-      "ish=pd/rsh\n",
-      "ia=i+ish\n",
-      "vda=ia*ra\n",
-      "E=pd+vda\n",
-      "cu_loss=(ia*ia*ra)+(pd*ish)\n",
-      "output_prime=(pd*i)+strayloss+cu_loss\n",
-      "power_a=output_prime-strayloss\n",
-      "neu_m=(power_a/output_prime)\n",
-      "neu_e=(pd*i)/((pd*i)+cu_loss)\n",
-      "neu_c=(pd*i)/output_prime\n",
-      "\n",
-      "#result\n",
-      "print \"a)e.m.f. generated= \",E,\" V\"\n",
-      "print \" b)Cu losses= \",cu_loss,\" W\"\n",
-      "print \" c)output of prime mover= \",output_prime,\" W\"\n",
-      "print \" d)mechanical efficiency= \",neu_m*100,\" %\"\n",
-      "print \"   electrical efficiency= \",neu_e*100,\" %\"\n",
-      "print \"   commercial efficiency= \",neu_c*100,\" %\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)e.m.f. generated=  254.0  V\n",
-        " b)Cu losses=  2050.0  W\n",
-        " c)output of prime mover=  51750.0  W\n",
-        " d)mechanical efficiency=  98.1642512077  %\n",
-        "   electrical efficiency=  95.9645669291  %\n",
-        "   commercial efficiency=  94.2028985507  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.24(b), Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "output=v*il\n",
-      "total_loss=(v*i*0.5)+((il+i*0.5)*(il+i*0.5)*ra)+(v*i*0.5)\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency=  87.8312542029  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.25, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=196#A\n",
-      "v=220#V\n",
-      "stray_loss=720#W\n",
-      "rsh=55#ohm\n",
-      "e=0.88\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "inpute=output/e\n",
-      "total_loss=inpute-output\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "cu_loss=v*ish\n",
-      "constant_loss=cu_loss+stray_loss\n",
-      "culoss_a=total_loss-constant_loss\n",
-      "ra=culoss_a/(ia*ia)\n",
-      "I=math.sqrt(constant_loss/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"Load curent corresponding to maximum efficiency\",I,\" A\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Load curent corresponding to maximum efficiency 122.283568103  A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.26, Page Number:929"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "p=22*1000#w\n",
-      "v=220#V\n",
-      "ra=0.05#ohm\n",
-      "rsh=110#ohm\n",
-      "rseries=0.06#ohm\n",
-      "efficiency=.88\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "I=p/v\n",
-      "ia=ish+I\n",
-      "vdseries=ia*rseries\n",
-      "cu_loss=(ia*ia*ra)+(ia*ia*rseries)+(rsh*ish*ish)\n",
-      "total_loss=(p/efficiency)-p\n",
-      "strayloss=total_loss-cu_loss\n",
-      "T=(p/efficiency*60)/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"a)cu losses= \",cu_loss,\" W\"\n",
-      "print \"b)iron and friction loss= \",strayloss,\" W\"\n",
-      "print \"c)Torque exerted by the prime mover= \",T,\" N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cu losses=  1584.44  W\n",
-        "b)iron and friction loss=  1415.56  W\n",
-        "c)Torque exerted by the prime mover=  238.853503185  N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.27, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "i=20#A\n",
-      "r=10#ohm\n",
-      "ra=0.5#ohm\n",
-      "rsh=50#ohm\n",
-      "vdb=1#V(voltage drop per brush)\n",
-      "\n",
-      "#calculations\n",
-      "v=i*r\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "E=v+(ia*ra)+(2*vdb)\n",
-      "totalpower=E*ia\n",
-      "output=v*i\n",
-      "efficiency=output/totalpower\n",
-      "\n",
-      "#result\n",
-      "print \"induced e.m.f.= \",E,\" V\"\n",
-      "print \"efficiency= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced e.m.f.=  214.0  V\n",
-        "efficiency=  77.8816199377  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.28, Page Number:930"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "i=100#A\n",
-      "ra=0.1#ohm\n",
-      "rseries=0.02#ohm\n",
-      "ri=0.025#ohm\n",
-      "rsh=100#ohm\n",
-      "ironloss=1000#W\n",
-      "frictionloss=500#W\n",
-      "\n",
-      "#calculations\n",
-      "output=v*i\n",
-      "totalra=ra+rseries+ri\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "copperloss=ia*ia*totalra\n",
-      "shculoss=ish*v\n",
-      "total_loss=copperloss+ironloss+frictionloss+shculoss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"F.L. efficiency of the machine= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "F.L. efficiency of the machine=  87.3089843128  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.31, Page Number:931"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=10.0*1000#W\n",
-      "v=240.0#V\n",
-      "ra=0.6#ohm\n",
-      "rsh=160.0#ohm\n",
-      "mechcoreloss=500.0#W\n",
-      "culoss=360.0#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rsh\n",
-      "i=output/v\n",
-      "ia=ish+i\n",
-      "culossa=ia*ia*ra\n",
-      "totalloss=culoss+mechcoreloss+culossa\n",
-      "inputp=output+totalloss\n",
-      "efficiency=output/inputp\n",
-      "\n",
-      "#result\n",
-      "print \"Power required= \",inputp*0.001,\" kW\"\n",
-      "print \"efficinecy= \",efficiency*100,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Power required=  11.9780166667  kW\n",
-        "efficinecy=  83.486275552  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.32, Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=110*1000#W\n",
-      "v=220#V\n",
-      "ra=0.01#ohm\n",
-      "rse=0.002#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "il=p/v\n",
-      "ish=v/rsh\n",
-      "ia=il+ish\n",
-      "E=v+ia*(ra+rse)\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf= \",E,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf=  226.024  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 26.33 Page Number:932"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "E=216.0#V\n",
-      "n=600.0#rpm\n",
-      "slots=144\n",
-      "con=6\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z=con*slots\n",
-      "a=p\n",
-      "phi=(E*60*a)/(n*z*p)\n",
-      "a=2\n",
-      "armatureE=(phi*z*n2*p)/(60*a)\n",
-      "\n",
-      "#result\n",
-      "print \"the armature emf= \",armatureE,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the armature emf=  360.0  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_1.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_1.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_2.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_2.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_3.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_3.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_4.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_4.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_5.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_5.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_6.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_6.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_7.ipynb
deleted file mode 100755
index 638b15f1..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter27_7.ipynb
+++ /dev/null
@@ -1,730 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02f2208937b2d82cdc7150d6d9062a1310b3e2fcf2346b8c885c3f6fe2fe5405"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 27: Armature Reaction and Commutation"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.1, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=722\n",
-      "ia=100.0#A\n",
-      "theta_m=8.0#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 802.222222222\n",
-        "cross-magnetization= 3710.27777778\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.2, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "z=1280\n",
-      "v=500#V\n",
-      "ia=200.0#A\n",
-      "commuter=160\n",
-      "advanced_segments=4\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/8\n",
-      "theta_m=advanced_segments*360/commuter\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 800.0\n",
-        "cross-magnetization= 1200.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(a), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=880\n",
-      "ia=120.0#A\n",
-      "theta_m=3.0#degrees\n",
-      "n=1100#tturns/pole\n",
-      "#calculatons\n",
-      "i=ia/2\n",
-      "atd_perpole=z*i*theta_m/360\n",
-      "atc_perpole=z*i*((1/(2.0*p))-(theta_m/360.0))\n",
-      "iadditional=(atd_perpole/n)\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"a)armature demagnetization=\",atd_perpole,\"AT\"\n",
-      "print \"b)cross-magnetization=\",atc_perpole,\"AT\"\n",
-      "print \"c)additional field current=\",iadditional,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)armature demagnetization= 440.0 AT\n",
-        "b)cross-magnetization= 6160.0 AT\n",
-        "c)additional field current= 0.4 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.3(b), Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=480\n",
-      "ia=150.0#A\n",
-      "theta_m=10.0*2#degrees\n",
-      "\n",
-      "#calculatons\n",
-      "i=ia/4\n",
-      "total=(z*i)/(2*p)\n",
-      "atd_perpole=total*(2*theta_m/180)\n",
-      "atc_perpole=total*(1-(2*theta_m/180))\n",
-      "\n",
-      "#result\n",
-      "print \"armature demagnetization=\",atd_perpole\n",
-      "print \"cross-magnetization=\",atc_perpole"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization= 500.0\n",
-        "cross-magnetization= 1750.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.4, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=492\n",
-      "theta_m=10.0\n",
-      "ia=143.0+10.0\n",
-      "\n",
-      "#calculations\n",
-      "i1=ia/2#wave wound\n",
-      "i2=ia/4#lap wound\n",
-      "atd_perpole1=z*i1*theta_m/360#wave wound\n",
-      "extra_shunt1=atd_perpole1/theta_m\n",
-      "atd_perpole2=z*i2*(theta_m/360.0)#lap wound\n",
-      "extra_shunt2=atd_perpole2/theta_m\n",
-      "#result\n",
-      "print \"wave wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole1,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt1)\n",
-      "print \"lap wound:\"\n",
-      "print \"demagnetization per pole=\",atd_perpole2,\"AT\"\n",
-      "print \"extra shunt field turns=\",int(extra_shunt2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "wave wound:\n",
-        "demagnetization per pole= 1045.5 AT\n",
-        "extra shunt field turns= 104\n",
-        "lap wound:\n",
-        "demagnetization per pole= 522.75 AT\n",
-        "extra shunt field turns= 52\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.5, Page Number:944"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pole=4\n",
-      "p=50*1000.0#W\n",
-      "v=250.0#V\n",
-      "z=400\n",
-      "commuter=4\n",
-      "rsh=50.0#ohm\n",
-      "a=2\n",
-      "\n",
-      "#calculations\n",
-      "i=p/v\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "i=ia/2\n",
-      "segments=z/a\n",
-      "theta=pole*360.0/segments\n",
-      "atd=z*i*(theta/360)\n",
-      "extra=atd/ish\n",
-      "\n",
-      "#result\n",
-      "print \"demagnetisation=\",atd,\"AT\"\n",
-      "print \"extra shunt turns/poles\",extra"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "demagnetisation= 820.0 AT\n",
-        "extra shunt turns/poles 164.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 35
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.6, Page Number:943"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=500\n",
-      "ia=200.0#A\n",
-      "p=6\n",
-      "theta=10.0#degrees\n",
-      "lambda_=1.3\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/2\n",
-      "atc=((1/(2.0*p))-(theta/360.0))*z*i\n",
-      "atd=z*i*theta/360\n",
-      "extra=lambda_*atd/ia\n",
-      "\n",
-      "#result\n",
-      "print \"i)cross magnetization ampere-turns=\",atc\n",
-      "print \"ii)back ampere-turns\",atd\n",
-      "print \"iii)series turns required to balance the demagnetising ampere turns\",int(extra)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)cross magnetization ampere-turns= 2777.77777778\n",
-        "ii)back ampere-turns 1388.88888889\n",
-        "iii)series turns required to balance the demagnetising ampere turns 9\n"
-       ]
-      }
-     ],
-     "prompt_number": 45
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.7, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=22.38#kW\n",
-      "v=440.0#V\n",
-      "pole=4\n",
-      "z=840\n",
-      "commutator=140\n",
-      "efficiency=0.88\n",
-      "ish=1.8#A\n",
-      "back=1.5\n",
-      "\n",
-      "#calculations\n",
-      "motor_input=p*1000.0/efficiency\n",
-      "input_i=motor_input/v\n",
-      "ia=input_i-ish\n",
-      "i=ia/2.0\n",
-      "theta=back*360/commutator\n",
-      "atd=z*i*(theta/360.0)\n",
-      "atc=((1/(2.0*pole))-(theta/360.0))*z*i\n",
-      "#result\n",
-      "print \"armature demagnetization amp-turns/pole=\",atd\n",
-      "print \"distorting amp-turns/pole=\",atc"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature demagnetization amp-turns/pole= 251.998140496\n",
-        "distorting amp-turns/pole= 2687.98016529\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.8, Page Number:945"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "ia=1000#A\n",
-      "p=10\n",
-      "z=860\n",
-      "per=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=ia/p\n",
-      "at=per/p*z*(i/2)\n",
-      "\n",
-      "#result\n",
-      "print \"AT/pole for compensation winding=\",at"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "AT/pole for compensation winding= 3010.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.9, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800.0#rpm\n",
-      "segment=123\n",
-      "wb=3\n",
-      "#calculations\n",
-      "v=n/60.0*segment\n",
-      "commutation=wb/v\n",
-      "\n",
-      "#result\n",
-      "print \"commutation time=\",commutation*1000,\"millisecond\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commutation time= 1.82926829268 millisecond\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.10, Page Number:948"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500#rpm\n",
-      "d=30#cm\n",
-      "ia=150#A\n",
-      "wb=1.25#cm\n",
-      "L=0.07*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "i=ia/2\n",
-      "v=3.14*d*(n/60)\n",
-      "tc=wb/v\n",
-      "E=L*2*i/tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 19.782 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.11, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "segments=55\n",
-      "n=900\n",
-      "wb=1.74\n",
-      "L=153*math.pow(10,-6)#H\n",
-      "i=27#A\n",
-      "\n",
-      "#calculations\n",
-      "v=segments*n/60\n",
-      "Tc=wb/v\n",
-      "E=L*2*i/Tc\n",
-      "\n",
-      "#result\n",
-      "print \"average emf=\",E,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "average emf= 3.91732758621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.12, Page Number:949"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=1500.0#rpm\n",
-      "ia=150.0#A\n",
-      "z=64\n",
-      "wb=1.2\n",
-      "L=0.05#mH\n",
-      "\n",
-      "#calculations\n",
-      "L=L*0.001\n",
-      "v=n/60*z\n",
-      "tc=wb/v\n",
-      "i=ia/p\n",
-      "#i.linear\n",
-      "E1=L*2*i/tc\n",
-      "#ii.sinusoidal\n",
-      "E2=1.11*E1\n",
-      "\n",
-      "#result\n",
-      "print \"Linear commutation,E=\",E1,\"V\"\n",
-      "print \"Sinosoidal commutation,E=\",E2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Linear commutation,E= 5.0 V\n",
-        "Sinosoidal commutation,E= 5.55 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.13, Page Number:951"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=6\n",
-      "B=0.5#Wb/m2\n",
-      "Ig=4.0#mm\n",
-      "ia=500.0#A\n",
-      "z=540\n",
-      "\n",
-      "#calculations\n",
-      "arm_mmf=z*(ia/p)/(2*p)\n",
-      "compole=int(B*Ig*0.001/(4*3.14*math.pow(10,-7)))\n",
-      "mag=0.1*compole\n",
-      "total_compole=int(compole+mag)\n",
-      "total_mmf=arm_mmf+total_compole\n",
-      "Ncp=total_mmf/ia\n",
-      "\n",
-      "#result\n",
-      "print \"Number of turns on each commutating pole=\",int(Ncp)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of turns on each commutating pole= 11\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.14, Page Number:957"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p1=100.0#kW\n",
-      "V1=250#V\n",
-      "p2=300.0#kW\n",
-      "V2=250#V\n",
-      "i1=200#A\n",
-      "i2=500#A\n",
-      "il=600#A\n",
-      "\n",
-      "#calculations\n",
-      "delI1=p1/(p1+p2)*il\n",
-      "delI2=p2/(p1+p2)*il\n",
-      "\n",
-      "#result\n",
-      "print \"Current supplied by generator 1 with additional load=\",delI1,\"A\"\n",
-      "print \"Current supplied by generator 2 with additional load=\",delI2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current supplied by generator 1 with additional load= 150.0 A\n",
-        "Current supplied by generator 2 with additional load= 450.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 92
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 27.23, Page Number:963"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "va=400#V\n",
-      "ra=0.25#ohm\n",
-      "vb=410#V\n",
-      "rb=0.4#ohm\n",
-      "V=390#V\n",
-      "\n",
-      "#calculations\n",
-      "loada=(va-V)/ra\n",
-      "loadb=(vb-V)/rb\n",
-      "pa=loada*V\n",
-      "pb=loadb*V\n",
-      "net_v=vb-va\n",
-      "total_r=ra+rb\n",
-      "i=net_v/total_r\n",
-      "terminal_v=va+(i*ra)\n",
-      "power_AtoB=terminal_v*i\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i,\"A\"\n",
-      "print \"Voltage=\",terminal_v,\"V\"\n",
-      "print \"Power=\",power_AtoB,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 15.3846153846 A\n",
-        "Voltage= 403.846153846 V\n",
-        "Power= 6213.01775148 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_1.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_1.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_2.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_2.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_3.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_3.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_4.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_4.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_5.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_5.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_6.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_6.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_7.ipynb
deleted file mode 100755
index 447ef8ab..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter28_7.ipynb
+++ /dev/null
@@ -1,388 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:6743417a1c79c6197a7cd49755318e10828c09b3cb248c5af8d5364367840700"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 28: Generator Characteristics"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.13, Page Number:984"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "#emf increases by 1 V for every increase of 6 A\n",
-      "ra=0.02#ohm\n",
-      "i=96#A\n",
-      "\n",
-      "#calculations\n",
-      "voltageincrease=i/6\n",
-      "vd=i*ra\n",
-      "voltage_rise=voltageincrease-vd\n",
-      "vconsumer=v+voltage_rise\n",
-      "power_supplied=voltage_rise*i\n",
-      "\n",
-      "#result\n",
-      "print \"voltage supplied ot consumer= \",vconsumer,\" V\"\n",
-      "print \"power supplied by the booster itself= \",power_supplied/1000,\" kW\" "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage supplied ot consumer=  234.08  V\n",
-        "power supplied by the booster itself=  1.35168  kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.14, Page Number:985"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#V\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=200.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "vd=i*r\n",
-      "voltage_decrease=v-vd\n",
-      "feeder_drop=v*r\n",
-      "booster_voltage=v*v/i1\n",
-      "voltage_net=feeder_drop-booster_voltage\n",
-      "\n",
-      "#result\n",
-      "print \"Net decrease in voltage= \",voltage_net,\" V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net decrease in voltage=  2.5  V\n"
-       ]
-      }
-     ],
-     "prompt_number": 6
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.15, Page Number:986"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "inl=5.0#A\n",
-      "v=440.0#V\n",
-      "il=6.0#A\n",
-      "i_full=200.0#A(full load)\n",
-      "turns=1600\n",
-      "\n",
-      "#calcuations\n",
-      "shunt_turns1=turns*inl\n",
-      "shunt_turns2=turns*il\n",
-      "increase=shunt_turns2-shunt_turns1\n",
-      "n=increase/i_full#number of series turns required\n",
-      "\n",
-      "#result\n",
-      "print \"Number of series turns required= \",n,\" tunrs/pole\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of series turns required=  8.0  tunrs/pole\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.16, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#turns/pole\n",
-      "series_winding=4#turns/pole\n",
-      "r=0.05#ohm\n",
-      "increase_i=0.2#A\n",
-      "ia=80#A\n",
-      "\n",
-      "#calculations\n",
-      "additional_at=n*increase_i\n",
-      "current_required=additional_at/series_winding\n",
-      "R=(current_required*r)/(ia-current_required)\n",
-      "\n",
-      "#result\n",
-      "print \"Divertor resistance= \",R,\" ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Divertor resistance=  0.0833333333333  ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.17, Page Number:987"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "i=100.0#A\n",
-      "ra=0.1#ohm\n",
-      "rsh=50.0#ohm\n",
-      "rse=0.06#ohm\n",
-      "divertor=0.14#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#short shunt\n",
-      "vd=i*rse\n",
-      "ish=v/rsh\n",
-      "ia=i+ish\n",
-      "armature_drop=ia*ra\n",
-      "E=v+vd+armature_drop\n",
-      "#long shunt\n",
-      "vd=ia*(ra+rse)\n",
-      "print vd\n",
-      "E2=v+vd\n",
-      "current_divertor=(ia*divertor)/(divertor+rse)\n",
-      "change=(current_divertor/ia)*100\n",
-      "\n",
-      "#result\n",
-      "print \"a)emf induced using short shunt= \",E\n",
-      "print \"b)emf induced using long shunt= \",E2\n",
-      "print \"c)series amp-turns are reduced to \",change,\" %\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "16.704\n",
-        "a)emf induced using short shunt=  236.44\n",
-        "b)emf induced using long shunt=  236.704\n",
-        "c)series amp-turns are reduced to  70.0  %\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.18, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=250*1000#W\n",
-      "v=240#V\n",
-      "v2=220#V\n",
-      "i=7#A\n",
-      "inl=12#A\n",
-      "shunt=650#turns/pole\n",
-      "series=4#turns/pole\n",
-      "rse=0.006#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i_fulload=p/v\n",
-      "shunt_increase=shunt*(inl-i)\n",
-      "ise=shunt_increase/series\n",
-      "i_d=i_fulload-ise\n",
-      "Rd=(ise*rse)/i_d\n",
-      "\n",
-      "#results\n",
-      "print \"resistance of the series amp-turns at no-load\",Rd,\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of the series amp-turns at no-load 0.0212751091703 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.19, Page Number:988"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "p=60.0*1000#W\n",
-      "n=1600.0#turns/pole\n",
-      "inl=1.25#A\n",
-      "vnl=125#V\n",
-      "il=1.75#A\n",
-      "vl=150.0#V\n",
-      "\n",
-      "#calculations\n",
-      "extra_excitation=n*(il-inl)\n",
-      "ise=p/vl\n",
-      "series=extra_excitation/ise\n",
-      "ise2=extra_excitation/3\n",
-      "i_d=ise-ise2\n",
-      "rd=(ise2*0.02)/i_d\n",
-      "reg=(vnl-vl)*100/vl\n",
-      "\n",
-      "#result\n",
-      "print \"i)minimum number of series turns/pole= \",series\n",
-      "print \"ii)divertor resistance= \",rd\n",
-      "print \"iii)voltage regulation= \",reg,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)minimum number of series turns/pole=  2.0\n",
-        "ii)divertor resistance=  0.04\n",
-        "iii)voltage regulation=  -16.6666666667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 28.20, Page Number:989"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=50.0#v\n",
-      "i=200.0#A\n",
-      "r=0.3#ohm\n",
-      "i1=160.0#A\n",
-      "i2=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#160 A\n",
-      "vd=i1*(r-(v/i))\n",
-      "#50 A\n",
-      "vd2=i2*(r-(v/i))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage drop at 160 A=\",vd,\"V\"\n",
-      "print \"voltage drop at 50 A=\",vd2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage drop at 160 A= 8.0 V\n",
-        "voltage drop at 50 A= 2.5 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_1.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_1.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_2.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_2.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_3.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_3.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_4.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_4.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_5.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_5.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_6.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_6.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_7.ipynb
deleted file mode 100755
index f3eda54f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter29_7.ipynb
+++ /dev/null
@@ -1,2343 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:f1e5688d45c7bb285838d2aad7b4c0c08dc93f4afbba4c253d97655938545a41"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 29: D.C. Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.1, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "r=0.5#ohm\n",
-      "i=20#A\n",
-      "\n",
-      "#calculation\n",
-      "#as generator \n",
-      "eg=v+i*r\n",
-      "#as motor\n",
-      "eb=v-i*r\n",
-      "\n",
-      "#result\n",
-      "print \"as generator:eg=\",eg,\"V\"\n",
-      "print \"as motor:eb=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "as generator:eg= 230.0 V\n",
-        "as motor:eb= 210.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.2, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia=Symbol('ia')\n",
-      "r=0.1#ohm\n",
-      "brush_drop=2#V\n",
-      "n=1000#rpm\n",
-      "i=100#A\n",
-      "v=250#V\n",
-      "n2=700#rpm\n",
-      "\n",
-      "#calculations\n",
-      "rl=v/i\n",
-      "eg1=v+i*r+brush_drop\n",
-      "eg2=eg1*n2/n\n",
-      "ia=solve(eg2-2-ia*r-2.5*ia,ia)\n",
-      "\n",
-      "#result\n",
-      "print \"current delivered to the load=\",ia[0],\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current delivered to the load= 69.7692307692308 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.3, Page Number:999"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.8#ohm\n",
-      "rf=200#ohm\n",
-      "output=7.46#kW\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=output*1000/efficiency\n",
-      "im=output*1000/(efficiency*v)\n",
-      "ish=v/rf\n",
-      "ia=im-ish\n",
-      "eb=v-ia*ra\n",
-      "\n",
-      "#results\n",
-      "print \"back emf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "back emf= 425.642780749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.4, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25#kW\n",
-      "v=250#V\n",
-      "ra=0.06#ohm\n",
-      "rf=100#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#as generator\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\"\n",
-      "\n",
-      "#as motor\n",
-      "i=load*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "power=eb*ia/1000\n",
-      "\n",
-      "print \"As generator: power=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "As generator: power= 26.12424 kW\n",
-        "As generator: power= 23.92376 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.5, Page Number:1000"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "z=32\n",
-      "v=200.0#V\n",
-      "i=12.0#A\n",
-      "ra=2.0#ohm\n",
-      "rf=200.0#ohm\n",
-      "n=1000.0#rpm\n",
-      "i2=5.0#A\n",
-      "#calculations\n",
-      "ia=i+v/rf\n",
-      "eg=v+ia*ra\n",
-      "phi=eg*a*60/(z*n*p)\n",
-      "#as motor\n",
-      "ia=i2-v/rf\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi,\"wb\"\n",
-      "print \"speed of the machine=\",math.ceil(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 0.42375 wb\n",
-        "speed of the machine= 850.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.6, Page Number:1002"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=110#A\n",
-      "v=480#V\n",
-      "ra=0.2#ohm\n",
-      "z=864\n",
-      "p=a=6\n",
-      "phi=0.05#Wb\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 636.0 rpm\n",
-        "the gross torque= 755.568 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.7, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "z=782\n",
-      "ra=rf=0.5#ohm\n",
-      "ia=40#A\n",
-      "phi=25*0.001#Wb\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=60*eb/(phi*z)\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "print \"the speed=\",math.floor(n),\"rpm\"\n",
-      "print \"the gross torque=\",ta,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the speed= 705.0 rpm\n",
-        "the gross torque= 248.676 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.8, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb=250.0#V\n",
-      "n=1500.0#rpm\n",
-      "ia=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "pm=eb*ia\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"machanical power=\",pm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 79.5833333333 N-m\n",
-        "machanical power= 12500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.9, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "z=800\n",
-      "load=8.2#kW\n",
-      "ia=45#A\n",
-      "phi=25*0.001#Wb\n",
-      "ra=0.6#ohm\n",
-      "a=p/2\n",
-      "\n",
-      "#calculation\n",
-      "ta=0.159*phi*z*ia*p/a\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a/(phi*z*p)\n",
-      "tsh=load*1000/(2*3.14*n)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",ta,\"N-m\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 286.2 N-m\n",
-        "shaft torque= 270.618131415 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 32
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.10, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=500.0#rpm\n",
-      "i=50.0#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=2*i\n",
-      "fb1=v-(i*ra)\n",
-      "eb2=v-(ia2*ra)\n",
-      "n2=eb2*n/fb1\n",
-      "#result\n",
-      "print \"speed when torque is doubled=\",n2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when torque is doubled= 476.19047619 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.11, Page Number:1003"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=500#V\n",
-      "load=37.3#kW\n",
-      "n=1000#rpm\n",
-      "efficiency=0.90\n",
-      "ra=0.24#ohm\n",
-      "vd=2#v\n",
-      "i=1.8#A\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "il=input_m/v\n",
-      "tsh=9.55*load*1000/n\n",
-      "il=ratio*il\n",
-      "ia=il-i\n",
-      "r=solve(ia*(r+ra)+vd-v,r)\n",
-      "\n",
-      "#result\n",
-      "print \"full-load line current=\",il,\"A\"\n",
-      "print \"full-load shaft torque\",tsh,\"N-m\"\n",
-      "print \"total resistance=\",r[0],\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load line current= 124.333333333 A\n",
-        "full-load shaft torque 356.215 N-m\n",
-        "total resistance= 3.82420021762787 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.12, Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=4\n",
-      "v=220#V\n",
-      "z=540\n",
-      "i=32#A\n",
-      "output=5.595#kW\n",
-      "ra=0.09#ohm\n",
-      "i_f=1#A\n",
-      "phi=30*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=i-i_f\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(phi*z*p)\n",
-      "tsh=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "print \"torque developed=\",tsh*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 804.481481481 rpm\n",
-        "torque developed= 66.4182473183 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(a), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "load=20.0#kW\n",
-      "i=5.0#A\n",
-      "ra=0.04#ohm\n",
-      "phi=0.04#Wb\n",
-      "z=160\n",
-      "il=95.0#A\n",
-      "inl=9.0#A\n",
-      "p=4\n",
-      "a=2\n",
-      "#calculation\n",
-      "#no load\n",
-      "ea0=v-(inl-i)*ra\n",
-      "n0=ea0*a*60/(phi*z*p)\n",
-      "#load\n",
-      "ea=v-(il-i)*ra\n",
-      "n=ea*n0/ea0\n",
-      "\n",
-      "#result\n",
-      "print \"no-load speed=\",n0,\"rpm\"\n",
-      "print \"load speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load speed= 1030.5 rpm\n",
-        "load speed= 1014.375 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(b), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=a=6\n",
-      "i=400#A\n",
-      "n=350#rpm\n",
-      "phi=80*0.001#Wb\n",
-      "z=600*2\n",
-      "loss=0.03#percentage\n",
-      "\n",
-      "#calculation\n",
-      "e=phi*z*n*p/(60*a)\n",
-      "pa=e*i\n",
-      "t=pa/(2*3.14*n/60)\n",
-      "t_net=0.97*t\n",
-      "bhp=t_net*36.67*0.001/0.746\n",
-      "#result\n",
-      "print \"brake-horse-power\",bhp,\"HP\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "brake-horse-power 291.551578696 HP\n"
-       ]
-      }
-     ],
-     "prompt_number": 66
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(c), Page Number:1004"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=774\n",
-      "phi=24*0.001#Wb\n",
-      "ia=50#A\n",
-      "a=2\n",
-      "#calculations\n",
-      "t=0.159*phi*z*ia*p/a\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 295.3584 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 67
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(d), Page Number:1005"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=200.0#ohm\n",
-      "il=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "ih=v/rf\n",
-      "pi=v*i\n",
-      "cu_loss_f=cu_loss=v*ih\n",
-      "output=v*il\n",
-      "cu_loss_a=(il+ih)**2*ra\n",
-      "total_loss=cu_loss+cu_loss_a+cu_loss_f\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 87.8312542029 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.13(e), Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delcration\n",
-      "ia=40#A\n",
-      "v=220#V\n",
-      "n=800#rpm\n",
-      "ra=0.2#ohm\n",
-      "rf=0.1#ohm\n",
-      "loss=0.5#kW\n",
-      "\n",
-      "#calculations\n",
-      "eb=v-ia*(ra+rf)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*(ra+rf)\n",
-      "total_loss=cu_loss+loss*1000\n",
-      "input_m=v*ia\n",
-      "output=input_m-total_loss\n",
-      "\n",
-      "#result\n",
-      "print \"output of the motor=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output of the motor= 7.82 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.14, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=400.0#N\n",
-      "d=10.0#cm\n",
-      "n=840#rpm\n",
-      "v=220.0#V\n",
-      "n1=1800#rpm\n",
-      "efficiency=.80\n",
-      "d2=24.0#cm\n",
-      "\n",
-      "#calculations\n",
-      "tsh=f*d*0.01/2\n",
-      "output=tsh*2*3.14*n/60\n",
-      "input_m=output/efficiency\n",
-      "i=input_m/v\n",
-      "d1=n*d2/n1\n",
-      "\n",
-      "#calculation\n",
-      "print \"current taken by the motor=\",round(i),\"A\"\n",
-      "print \"size of motor pulley=\",d1,\"cm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the motor= 10.0 A\n",
-        "size of motor pulley= 11.2 cm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.15, Page Number:1006"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "p=4\n",
-      "z=280\n",
-      "ia=45.0#A\n",
-      "phi=18*0.001#Wb\n",
-      "ra=0.5+0.3#ohm\n",
-      "loss=800.0#W\n",
-      "d=0.41\n",
-      "a=4\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "n=eb*60*a/(phi*z*p*4)\n",
-      "inpt=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=loss+cu_loss\n",
-      "output=inpt-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "f=tsh*2/d\n",
-      "\n",
-      "#result\n",
-      "print \"pull at the rim of the pulley=\",f,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pull at the rim of the pulley= 628.016180845 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.16, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=240#V\n",
-      "output=11.19#kW\n",
-      "n=1000#rpm\n",
-      "ia=50#A\n",
-      "i=1#A\n",
-      "z=540\n",
-      "ra=0.1#ohm\n",
-      "vd=1#V\n",
-      "a=2\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "tsh=9.55*output*1000/n\n",
-      "phi=eb*60*a*1000/(z*n*p)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "brush_loss=ia*2\n",
-      "power=input_a-(cu_loss+brush_loss)\n",
-      "rotational_loss=power-output*1000\n",
-      "input_m=v*(ia+i)\n",
-      "efficiency=output*1000/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"total torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"flux/pole=\",phi,\"mWb\"\n",
-      "print \"rotational losses=\",rotational_loss,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "total torque= 112.2125 N-m\n",
-        "useful torque= 106.8645 N-m\n",
-        "flux/pole= 13.0555555556 mWb\n",
-        "rotational losses= 460.0 W\n",
-        "efficiency= 91.4215686275 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 106
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.17, Page Number:1007"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#v\n",
-      "n=500.0#rpm\n",
-      "i=40.0#A\n",
-      "i2=30.0#A\n",
-      "ra=0.8#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t2_by_t1=i2**2/i**2\n",
-      "change=(1-t2_by_t1)*100#percentage\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-i2*ra\n",
-      "n2=eb2*i*n/(eb1*i2)\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"percentage change in torque=\",change,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 679.127725857 rpm\n",
-        "percentage change in torque= 43.75 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.18, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "output=55.95#kW\n",
-      "n=750#rpm\n",
-      "I=252.8#kg-m2\n",
-      "ia1=1.4\n",
-      "ia2=1.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ia1+ia2)/2\n",
-      "n=n/60.0\n",
-      "tsh=output*1000/(2*3.14*n)\n",
-      "torque_avg=(ia-1)*tsh\n",
-      "dt=(I*2*3.14*n)/torque_avg\n",
-      "\n",
-      "#result\n",
-      "print \"approximate time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "approximate time to attain full speed= 46.4050282991 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.19, Page Number:1008"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "v=400.0#V\n",
-      "n=400.0#rpm\n",
-      "i=40.0#A\n",
-      "I=7.5#kg-m2\n",
-      "ratio=1.2\n",
-      "\n",
-      "#calculations\n",
-      "n=n/60\n",
-      "t=output*1000/(2*3.14*n)\n",
-      "torque=(ratio-1)*t\n",
-      "dt=(I*2*3.14*n)/torque\n",
-      "\n",
-      "print \"time to attain full speed=\",dt,\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "time to attain full speed= 4.4055406613 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 138
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.20, Page Number:1009"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "z=944\n",
-      "phi=34.6*0.001#Wb\n",
-      "ta=209.0#N-m\n",
-      "v=500.0#V\n",
-      "ra=3.0#ohm\n",
-      "a=2\n",
-      "#calculation\n",
-      "ia=ta/(0.159*phi*z*(p/a))\n",
-      "ea=v-ia*ra\n",
-      "n=ea/(phi*z*(p/a))\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",ia,\"A\"\n",
-      "print \"speed=\",n*60,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 20.1219966813 A\n",
-        "speed= 403.798260345 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.21, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#v\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i2=50#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb0=v-(ia-ish)*ra\n",
-      "eb=v-(i2-ish)*ra\n",
-      "n=eb*n/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"speed when loaded=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when loaded= 966.21078037 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.22, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=800#rpm\n",
-      "ia=100#A\n",
-      "v=230#V\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "ia2=25#A\n",
-      "ratio=0.45\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor runs=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor runs= 1940.37940379 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.23, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=115.0#ohm\n",
-      "n1=1200#rpm\n",
-      "ia=2.5#A\n",
-      "n2=1120#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ra*ia\n",
-      "x=n2*eb1/n1\n",
-      "ia2=solve((v-ra*ia2)-x,ia2)\n",
-      "ia=ia2[0]+(v/rf)\n",
-      "input_m=v*ia\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",round(ia,1),\"A\"\n",
-      "print \"power input=\",round(input_m,1),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= 35.0 A\n",
-        "power input= 8050.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.24, Page Number:1010"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=100.0#kW\n",
-      "n1=300#rpm\n",
-      "v=220.0#V\n",
-      "load=10.0#kW\n",
-      "ra=0.025#ohm\n",
-      "rf=60.0#ohm\n",
-      "vd=1.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i=power*1000/v\n",
-      "ish=v/rf\n",
-      "ia=i+ish\n",
-      "eb=v+ia*ra+2*vd\n",
-      "i=load*1000/v\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n1/eb\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 278.796797778 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.25, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by whih armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia2=ia-ish\n",
-      "eb0=v-ia2*ra\n",
-      "n0=n*eb0/v\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n0/(eb0*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed of machine=\",math.floor(n),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of machine= 960.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.26, Page Number:1011"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ooutput=14.92#kW\n",
-      "n=1000#rpm\n",
-      "i=75#A\n",
-      "ra=0.25#ohm\n",
-      "ratio=0.20\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb_inst=eb1*(1-ratio)\n",
-      "ia_inst=(v-eb_inst)/ra\n",
-      "t_inst=9.55*eb_inst*ia_inst/n\n",
-      "ia2=i/(1-ratio)\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 93.75 A\n",
-        "speed= 1224.66216216 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 191
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.27, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "i=4.0#A\n",
-      "n=700.0#rpm\n",
-      "rf=100.0#A\n",
-      "v2=6.0#V\n",
-      "i2=10.0#A\n",
-      "input_m=8.0#kW\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "il=input_m*1000/v\n",
-      "ia=il-ish\n",
-      "ra=v2/i2\n",
-      "eb0=v-ish*ra\n",
-      "eb=v-ia*ra\n",
-      "n=eb*n/eb0\n",
-      "ta=9.55*eb*ia/n\n",
-      "inpt=v*i\n",
-      "cu_loss=ish**2*ra\n",
-      "constant_loss=inpt-cu_loss\n",
-      "cu_loss_arm=ia**2*ra\n",
-      "total_loss=constant_loss+cu_loss_arm\n",
-      "output=input_m*1000-total_loss\n",
-      "efficiency=output/(input_m*1000)\n",
-      "print \n",
-      "#result\n",
-      "print \"speed on load=\",n,\"rpm\"\n",
-      "print \"torque=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "speed on load= 623.943661972 rpm\n",
-        "torque= 103.0636 N-m\n",
-        "efficiency= 79.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 197
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.28, Page Number:1012"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "v=220#V\n",
-      "load=11#kW\n",
-      "inl=5#A\n",
-      "n_nl=1150#rpm\n",
-      "ra=0.5#ohm\n",
-      "rsh=110#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=v*inl\n",
-      "ish=v/rsh\n",
-      "ia0=inl-ish\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "i=load*1000/v\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "total_loss=cu_loss_a+constant_loss\n",
-      "output=load*1000-total_loss\n",
-      "efficiency=output*100/(load*1000)\n",
-      "eb_nl=v-(ia0*ra)\n",
-      "eb=v-ia*ra\n",
-      "n=n_nl*eb/eb_nl\n",
-      "ta=9.55*eb*ia/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"the speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque developed= 87.096 N-m\n",
-        "efficiency= 79.5361818182 %\n",
-        "the speed= 1031.57894737 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.29, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=250.0#V\n",
-      "ra=0.1#ohm\n",
-      "vb=3#V\n",
-      "rf=0.05#ohm\n",
-      "ia=80.0#A\n",
-      "n=600.0#rpm\n",
-      "i2=100.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-i2*(ra+rf)\n",
-      "n2=eb2*ia*n/(eb1*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed when current is 100 A=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when current is 100 A= 473.949579832 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.30, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "n=800.0#rpm\n",
-      "i=100.0#A\n",
-      "ra=0.1\n",
-      "ratio=1.0/2.0\n",
-      "#calculation\n",
-      "ia1=i*math.sqrt(ratio)\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-ia1*ra\n",
-      "n2=eb2*i*n/(eb1*ia1)\n",
-      "#result\n",
-      "print \"speed when motor will run when developing half the torque=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when motor will run when developing half the torque= 1147.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.31, Page Number:1013"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=a=4\n",
-      "n=600#rpm\n",
-      "ia=25#A\n",
-      "v=450#V\n",
-      "z=500\n",
-      "phi=1.7*0.01*math.pow(ia,0.5)\n",
-      "\n",
-      "#calculation\n",
-      "eb=n*phi*z*p/(60*a)\n",
-      "iara=v-eb\n",
-      "ra=iara/ia\n",
-      "i=math.pow((phi*ia*math.sqrt(ia)/(phi*2)),2.0/3.0)\n",
-      "eb2=v/2-i*ra\n",
-      "phi2=1.7*0.01*math.pow(i,0.5)\n",
-      "n2=eb2*phi*n/(eb*phi2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which motor will run=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which motor will run= 372.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 224
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.32, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "v=460.0#V\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "def f(ia,t):\n",
-      "    n=(v*ia-ia**2*ra)*60/(2*3.14*t)\n",
-      "    return(n)\n",
-      "\n",
-      "n1=f(20.0,128.8)\n",
-      "n2=f(30.0,230.5)\n",
-      "n3=f(40.0,349.8)\n",
-      "n4=f(50.0,469.2)\n",
-      "T=[128.8,230.5,349.8,469.2]\n",
-      "N=[n1,n2,n3,n4]\n",
-      "a=plot(T,N)\n",
-      "xlabel(\"Torque(NM.m)\") \n",
-      "ylabel(\"Speed(rpm)\") \n",
-      "plt.xlim((0,500))\n",
-      "plt.ylim((0,800))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.33, Page Number:1017"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "#variable declaration\n",
-      "output=5.968#kW\n",
-      "n=700#rpm\n",
-      "v1=500#V\n",
-      "n2=600#rpm\n",
-      "ra=3.5#ohm\n",
-      "loss=450#W\n",
-      "\n",
-      "#calculation\n",
-      "\n",
-      "def fp(i,v):\n",
-      "    p=5.968*((n2*(v1-i*ra)/(v*n))**2)\n",
-      "    return(p)\n",
-      "\n",
-      "def fm(i,v):\n",
-      "    m=((v1-i*ra)*i-loss)/1000\n",
-      "    return(m)\n",
-      "\n",
-      "p1=fp(7.0,347.0)\n",
-      "p2=fp(10.5,393.0)\n",
-      "p3=fp(14.0,434.0)\n",
-      "p4=fp(27.5,468.0)\n",
-      "\n",
-      "m1=fm(7.0,347.8)\n",
-      "m2=fm(10.5,393.0)\n",
-      "m3=fm(14.0,434.0)\n",
-      "m4=fm(27.5,468.0)\n",
-      "\n",
-      "#plot\n",
-      "I=[7,10.5,14,27.5]\n",
-      "P=[p1,p2,p3,p4]\n",
-      "M=[m1,m2,m3,m4]\n",
-      "a=plot(I,P)\n",
-      "a=plot(I,M)\n",
-      "xlabel(\"Current\") \n",
-      "ylabel(\"Power(kW)\") \n",
-      "plt.xlim((0,30))\n",
-      "plt.ylim((0,12))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.34, Page Number:1022"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "i=3#A\n",
-      "ia=3.5#A\n",
-      "ib=4.5#A\n",
-      "\n",
-      "#calculation\n",
-      "loss=v*i\n",
-      "#B unexcited\n",
-      "loss1=v*(ia-i)\n",
-      "#B excited\n",
-      "loss2=v*(ib-i)\n",
-      "loss=loss2-loss1\n",
-      "\n",
-      "#result\n",
-      "print \"iron losses of B=\",loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "iron losses of B= 500.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.35, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.2#ohm\n",
-      "rf=110.0#ohm\n",
-      "ia=5.0#A\n",
-      "n=1500#rpm\n",
-      "i2=52.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i2-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=round(eb2*n/eb1,0)\n",
-      "input_nl=v*ia\n",
-      "cu_loss_nl=ia1**2*ra\n",
-      "constant_loss=input_nl-cu_loss_nl\n",
-      "cu_loss_l=ia2**2*ra\n",
-      "total_loss=constant_loss+cu_loss_l\n",
-      "input_l=v*i2\n",
-      "output=input_l-total_loss\n",
-      "tsh=9.55*output/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.36, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=5#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "ratio=0.03#percentage by which armature reaction weakens field\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "ia2=i-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 994.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 241
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.37, Page Number:1023"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ia=5#A\n",
-      "ra=0.22#A\n",
-      "rf=250#ohm\n",
-      "i=100#A\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia0=ia-ish\n",
-      "eb0=v-ia0*ra\n",
-      "cu_loss=ia0**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "cu_loss=ia**2*ra\n",
-      "total_loss=cu_loss+constant_loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "efficiency=output*100/input_m\n",
-      "per=(eb-eb0)*100/eb0\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\"\n",
-      "print \"percentage change in speed=\",round(per,2),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 90.8 %\n",
-        "percentage change in speed= -4.19 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 244
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.38, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "i=25#A\n",
-      "i2=50#A\n",
-      "ratio=0.03#percentage by which the armature reaction weakens field\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "vd=1\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ebh=v-ia1*ra-2*vd\n",
-      "ia2=i2-ish\n",
-      "eb2=v-ia2*ra-2*vd\n",
-      "n2=eb2*n/(ebh*(1-ratio))\n",
-      "ta1=9.55*eb1*ia1/n\n",
-      "ta2=9.55*eb2*ia2/n2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"torque in first case=\",ta1,\"N-m\"\n",
-      "print \"torque in second case=\",ta2,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1010.0 rpm\n",
-        "torque in first case= 57.11664 N-m\n",
-        "torque in second case= 110.3912768 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 247
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.39, Page Number:1024"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "n1=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "ia=4.0#A\n",
-      "i=40.0#A\n",
-      "ratio=0.04#percentage by which the armature reaction weakens field\n",
-      "eb1=250.0#V\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "eb2=v-(i-ish)*ra\n",
-      "n2=eb2*n/(eb1*(1-ratio))\n",
-      "cu_loss=(ia-ish)**2*ra\n",
-      "input_m=v*ia\n",
-      "constant_loss=input_m-cu_loss\n",
-      "cu_loss_a=(i-ish)**2*ra\n",
-      "total_loss=constant_loss+cu_loss_a\n",
-      "inpt=v*i\n",
-      "output=inpt-total_loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 960.0 rpm\n",
-        "efficiency= 82.44 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 254
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.40, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "v=250#V\n",
-      "z=120*8\n",
-      "a=4\n",
-      "phi=20*0.001#Wb\n",
-      "i=25#A\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "loss=810#W\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_shunt=v*ish\n",
-      "total_loss=loss+cu_loss+cu_loss_shunt\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque=\",ta,\"N-m\"\n",
-      "print \"useful torque=\",tsh,\"N-m\"\n",
-      "print \"efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque= 70.288 N-m\n",
-        "useful torque= 60.2946209124 N-m\n",
-        "efficiency= 78.1936 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 256
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.41, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=14.92#kW\n",
-      "n=1150#rpm\n",
-      "p=4\n",
-      "a=2\n",
-      "z=620\n",
-      "ra=0.2#ohm\n",
-      "i=74.8#A\n",
-      "i2=3#A\n",
-      "v=230#V\n",
-      "#calculation\n",
-      "ia=i-i2\n",
-      "eb=v-ia*ra\n",
-      "phi=eb*a*60/(p*z*n)\n",
-      "ta=9.55*eb*ia/n\n",
-      "power=eb*ia\n",
-      "loss_rot=power-output*1000\n",
-      "input_m=v*i\n",
-      "total_loss=input_m-output*1000\n",
-      "per=total_loss*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"flux per pole=\",phi*1000,\"mWb\"\n",
-      "print \"torque developed=\",ta,\"N-m\"\n",
-      "print \"rotational losses=\",loss_rot,\"W\"\n",
-      "print \"total losses expressed as a percentage of power=\",per,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "flux per pole= 9.07321178121 mWb\n",
-        "torque developed= 128.575818783 N-m\n",
-        "rotational losses= 562.952 W\n",
-        "total losses expressed as a percentage of power= 13.2759823297 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 263
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.42, Page Number:1025"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=7.46#kW\n",
-      "v=250#V\n",
-      "i=5#A\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "\n",
-      "#calculation\n",
-      "input_m=v*i\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "cu_loss=v*ish\n",
-      "cu_loss_a=ra*ia**2\n",
-      "loss=input_m-cu_loss\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output*1000+loss,ia1)\n",
-      "i2=ia1[0]+ish\n",
-      "input_m1=v*i2\n",
-      "efficiency=output*100000/input_m1\n",
-      "ia=math.sqrt((input_m-cu_loss_a)/ra)\n",
-      "input_a=v*ia\n",
-      "cu_loss=ia**2*ra\n",
-      "output_a=input_a-(cu_loss+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"output power at which efficiency is maximum=\",output_a/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 79.5621535016683 %\n",
-        "output power at which efficiency is maximum= 10.2179357944 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 271
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.43, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n2_by_n1=1.0/2.0\n",
-      "ia2_by_ia1=phi1_by_phi2=1.0/2.0\n",
-      "v2_by_v1=n2_by_n1*phi1_by_phi2\n",
-      "reduction_v=(1-v2_by_v1)*100\n",
-      "reduction_i=(1-ia2_by_ia1)*100\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction in the motor terminal voltage=\",reduction_v,\"%\"\n",
-      "print \"percentage fall in the motor current=\",reduction_i,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in the motor terminal voltage= 75.0 %\n",
-        "percentage fall in the motor current= 50.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 272
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.44, Page Number:1026"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=500#V\n",
-      "z=1200\n",
-      "phi=20*0.001#Wb\n",
-      "ra=0.5#ohm\n",
-      "rf=250#ohm\n",
-      "i=20#A\n",
-      "loss=900#W\n",
-      "a=2\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "n=eb*a*60/(p*z*phi)\n",
-      "ta=9.55*eb*ia/n\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_loss=cu_loss+cu_loss_f+loss\n",
-      "input_m=v*i\n",
-      "output=input_m-total_loss\n",
-      "tsh=9.55*output/n\n",
-      "efficiency=output*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"useful torque=\",ta,\"N-m\"\n",
-      "print \"output=\",output/1000,\"Kw\"\n",
-      "print \"efficiency==\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "useful torque= 206.28 N-m\n",
-        "output= 7.938 Kw\n",
-        "efficiency== 79.38 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 29.45, Page Number:1027"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia1=Symbol('ia1')\n",
-      "output=37.3*1000#W\n",
-      "v=460#V\n",
-      "i=4#A\n",
-      "n=660#rpm\n",
-      "ra=0.3#ohm\n",
-      "rf=270#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "cu_loss=v*ish\n",
-      "ia=i-ish\n",
-      "cu_loss_a=ia**2*ra\n",
-      "input_a=loss=v*ia\n",
-      "ia1=solve(ra*ia1**2-v*ia1+output+loss,ia1)\n",
-      "i=ia1[0]+ish\n",
-      "eb1=v-(ia*ra)\n",
-      "eb2=v-(ia1[0]*ra)\n",
-      "n2=n*eb2/eb1\n",
-      "ia=math.sqrt((cu_loss+input_a)/ra)\n",
-      "\n",
-      "#result\n",
-      "print \"the current input=\",i,\"A\"\n",
-      "print \"speed=\",round(n2,0),\"rpm\"\n",
-      "print \"armature current at which efficiency is maximum=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the current input= 90.2860908863713 A\n",
-        "speed= 623.0 rpm\n",
-        "armature current at which efficiency is maximum= 78.3156008298 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 280
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_1.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_1.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_2.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_2.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_3.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_3.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_4.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_4.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_5.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_5.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_6.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_6.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_7.ipynb
deleted file mode 100755
index ce13ea95..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter30_7.ipynb
+++ /dev/null
@@ -1,2629 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:072a977ff7e7f41108f647b699866e16f58bf91b148a03cefc5a07bc1eeda05b"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 30:Speed Control of D.C. Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.1, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "n=250#rpm\n",
-      "ia=200#A\n",
-      "ra=0.12#ohm\n",
-      "ratio=0.80\n",
-      "ia2=100#A\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 320.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.2, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ra=0.25#ohm\n",
-      "ia=50#A\n",
-      "n=750#rpm\n",
-      "ratio=1-0.10\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia/ratio\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 828.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1032"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=800#rpm\n",
-      "ia=50.0#A\n",
-      "n2=1000#rpm\n",
-      "ia2=80.0#A\n",
-      "ra=0.15#ohm\n",
-      "rf=250.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ish1=v/rf\n",
-      "r1=(n2*eb1*v)/(n*eb2*ish1)\n",
-      "r=r1-rf\n",
-      "ish2=v/r1\n",
-      "torque_ratio=ish2*ia2/(ish1*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\"\n",
-      "print \"ratio of torque=\",torque_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 68.9506880734 ohm\n",
-        "ratio of torque= 1.25411235955\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.3, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "rf=250.0#ohm\n",
-      "ra=0.25#ohm\n",
-      "n=1500#rpm\n",
-      "ia=20.0#A\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ish2=v/(rf+r)\n",
-      "ia2=ia*1/ish2\n",
-      "eb2=v-ia2*ra\n",
-      "eb1=v-ia*ra\n",
-      "n2=eb2*n/(eb1*ish2)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",round(n2),\"rpm\"\n",
-      "print \"new armature current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 2939.0 rpm\n",
-        "new armature current= 40.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 23
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.5, Page Number:1033"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "rt=Symbol('rt')\n",
-      "v=250.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=250.0#ohm\n",
-      "n=600.0#rpm\n",
-      "ia=20.0#A\n",
-      "n2=800.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ish1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "rt=solve(((n2*eb1*(v/rt))/(n*(v-(ia*ra/(v/rt)))))-1,rt)\n",
-      "r=rt[0]-rf\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 88.3128987990058 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.6, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=1+0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "x=solve((ratio*eb1/((v-ia*ra*x)*x))-1,x)\n",
-      "per=1-1/x[0]\n",
-      "\n",
-      "#result\n",
-      "print\"main flux has to be reduced by=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "main flux has to be reduced by= 37.2991677469778 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.7, Page Number:1034"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=10#kW\n",
-      "i=41#A\n",
-      "ra=0.2#ohm\n",
-      "rw=0.05#ohm\n",
-      "ri=0.1#ohm\n",
-      "rf=110#ohm\n",
-      "ratio=1-0.25\n",
-      "r=1#ohm\n",
-      "ratio1=1-0.50\n",
-      "n=2500\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ratio1*ia1/ratio\n",
-      "eb1=v-ia1*(ra+ri+rw)\n",
-      "eb2=v-ia2*(r+ra+ri+rw)\n",
-      "n2=eb2*n/(eb1*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"motor speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 26.0 A\n",
-        "motor speed= 2987.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.8, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "load=15#kW\n",
-      "n=850#rpm\n",
-      "ia=72.2#A\n",
-      "ra=0.25#ohm\n",
-      "rf=100#ohm\n",
-      "n2=1650#rpm\n",
-      "ia2=40#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "ratio=(n*eb2)/(n2*eb1)\n",
-      "per=1-ratio\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 46.5636857585 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.9, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40#A\n",
-      "ratio=0.50+1\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "ia2=solve((((v-ra*ia2)*ia2)/(eb1*ratio*ia))-1,ia2)\n",
-      "per=ia/ia2[0]\n",
-      "\n",
-      "#result\n",
-      "print \"mail flux should be reduced by=\",round(per,4)*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mail flux should be reduced by= 62.7 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.10, Page Number:1035"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=20.0#A\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ratio=0.50\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "eb2=ratio*(v-ia*ra)\n",
-      "r=(v-eb2)/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in the series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in the series= 5.25 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.11, Page Number:1036"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ia=8#A\n",
-      "i_f=1#A\n",
-      "ra=0.2#ohm\n",
-      "rf=250#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "eb0=v-(ia-i_f)*ra\n",
-      "kpsi=eb0/1000\n",
-      "ia=i-i_f\n",
-      "eb1=v-ia*ra\n",
-      "n1=eb1/kpsi\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",round(n1,1),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 966.2 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.12, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240#V\n",
-      "ra=0.25#ohm\n",
-      "n=1000#rpm\n",
-      "ia=40#A\n",
-      "n2=800#rpm\n",
-      "i2=20#A\n",
-      "#calculation\n",
-      "eb=v-ia*ra\n",
-      "eb2=n2*eb/n\n",
-      "r=(v-eb2)/(ia)-ra\n",
-      "eb3=v-i2*(r+ra)\n",
-      "n3=eb3*n/eb\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\"\n",
-      "print \"speed=\",round(n3),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 1.15 ohm\n",
-        "speed= 922.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.13, Page Number:1037"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.48#kW\n",
-      "v=220#V\n",
-      "n=990#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2#A\n",
-      "n2=450#rpm\n",
-      "\n",
-      "#calculation\n",
-      "input_p=load*1000/efficiency\n",
-      "losses=input_p-load*1000\n",
-      "i=input_p/v\n",
-      "ia=i-ish\n",
-      "loss=v*ish\n",
-      "cu_loss=ia**2*ra\n",
-      "loss_nl=losses-cu_loss-loss\n",
-      "eb1=v-20-(ia*ra)\n",
-      "eb2=n2*eb1/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "total_loss=ia**2*(r+ra)+loss+loss_nl\n",
-      "output=input_p-total_loss\n",
-      "efficiency=output/(input_p)\n",
-      "\n",
-      "#result\n",
-      "print \"motor input=\",input_p/1000,\"kW\"\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor input= 8.5 kW\n",
-        "armature current= 36.6363636364 A\n",
-        "external resistance= 2.93403113016 ohm\n",
-        "efficiency= 41.6691237902 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.14, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "eb1=230.0#V\n",
-      "n=990.0#rpm\n",
-      "n2=500.0#rpm\n",
-      "ia=25.0#A\n",
-      "\n",
-      "#calculation\n",
-      "eb2=eb1*n2/n\n",
-      "r=(eb1-eb2)/ia\n",
-      "\n",
-      "#result\n",
-      "print \"resistance required in series=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance required in series= 4.55353535354 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 83
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.15, Page Number:1038"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=20.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k2=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "rf1=v/if1\n",
-      "rf2=v/if2\n",
-      "r=rf2-rf1\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 100.0 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.16, Page Number:1039"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "ia2=Symbol('ia2')\n",
-      "v=220.0#V\n",
-      "ra=0.4#ohm\n",
-      "rf=200.0#ohm\n",
-      "ia=22.0#A\n",
-      "n=600.0#rpm\n",
-      "n2=900.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "if1=v/rf\n",
-      "eb1=v-ia*ra\n",
-      "k1=eb1/(if1*n)\n",
-      "if2=n*if1/n2\n",
-      "if2=n2*ia/n\n",
-      "ia2=solve(v-ra*ia2-(k1*ia*if1*n2)/ia2,ia2)\n",
-      "if2=ia*if1/ia2[0]\n",
-      "r=v/if2\n",
-      "\n",
-      "#result\n",
-      "print \"new field resistance to be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new field resistance to be added= 306.828780053869 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.17, Page Number:1040"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "output=25#kW\n",
-      "efficiency=0.85\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=125#ohm\n",
-      "ratio=1.50\n",
-      "\n",
-      "#calculation\n",
-      "input_p=output*1000/efficiency\n",
-      "i=input_p/v\n",
-      "if1=v/rf\n",
-      "ia=i-if1\n",
-      "il=ratio*ia\n",
-      "r=v/il\n",
-      "r_ext=r-ra\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",round(r_ext,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 1.341 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.18, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "n=1000.0#rpm\n",
-      "ia=17.5#A\n",
-      "n2=600.0#rpm\n",
-      "ra=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "rt=(v-(n2*eb1/n))/ia\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resistance to be inserted=\",round(r,1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be inserted= 4.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.19, Page Number:1042"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500#V\n",
-      "ra=1.2#ohm\n",
-      "rf=500#ohm\n",
-      "ia=4#A\n",
-      "n=1000#rpm\n",
-      "i=26#A\n",
-      "r=2.3#ohm\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=ia-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=i-ish\n",
-      "eb2=v-ia2*ra\n",
-      "n2=n*eb2/eb1\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2_=n*eb2/eb1\n",
-      "n2__=n*eb2/(eb1*(1-ratio))\n",
-      "\n",
-      "#result\n",
-      "print \"speed when resistance 2.3 ohm is connected=\",round(n2_),\"rpm\"\n",
-      "print \"speed when shunt field is reduced by 15%=\",round(n2__),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when resistance 2.3 ohm is connected= 831.0 rpm\n",
-        "speed when shunt field is reduced by 15%= 978.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.20, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ia1=ia2=20.0#A\n",
-      "n=1000.0#rpm\n",
-      "ra=0.5#ohm\n",
-      "n2=500.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia1*ra\n",
-      "rt=(v-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "ia3=ia2/2\n",
-      "n3=n*(v-ia3*rt)/eb1\n",
-      "#result\n",
-      "print \"speed=\",round(n3),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 771.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.21, Page Number:1043"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=600.0#rpm\n",
-      "ia2=ia1=20#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "#torque is half the full-load torque\n",
-      "ia2=1.0/2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at half full-load torque=\",round(n2_),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 550.0 rpm\n",
-        "speed at half full-load torque= 588.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 137
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.22, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra1=0.5#ohm\n",
-      "n=500.0#rpm\n",
-      "ia2=ia1=30.0#A\n",
-      "r=1.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "eb1=v-ia1*ra1\n",
-      "ra2=r+ra1\n",
-      "eb2=v-ia2*ra2\n",
-      "n2=eb2*n/eb1\n",
-      "\n",
-      "#torque is half the full-load torque\n",
-      "ia2=2.0*ia1\n",
-      "eb22=v-ia2*ra2\n",
-      "n2_=eb22*n/eb1\n",
-      "#result\n",
-      "print \"speed at full load torque=\",round(n2),\"rpm\"\n",
-      "print \"speed at double full-load torque=\",round(n2_),\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at full load torque= 427.0 rpm\n",
-        "speed at double full-load torque= 317.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.23, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3*1000#W\n",
-      "v=500.0#V\n",
-      "n=750.0#rpm\n",
-      "efficiency=0.90\n",
-      "t2=250.0#N-m\n",
-      "r=5.0#ohm\n",
-      "ra=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "t1=load/(2*3.14*(n/60))\n",
-      "ia1=load/(efficiency*v)\n",
-      "ia2=ia1*math.sqrt(t2/t1)\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*(r+ra)\n",
-      "n2=eb2*ia1*n/(eb1*ia2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed at which machine will run=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which machine will run= 381.789716486 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.24, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=7.46*1000#W\n",
-      "v=220.0#V\n",
-      "n=900.0#rpm\n",
-      "efficiency=0.88\n",
-      "ra=0.08#ohm\n",
-      "ish=2.0#A\n",
-      "n2=450.0#rpm\n",
-      "#calculation\n",
-      "i=output/(efficiency*v)\n",
-      "ia2=ia1=i-ish\n",
-      "eb1=v-ia2*ra\n",
-      "rt=(v-20-((n2/n)*eb1))/ia2\n",
-      "r=rt-ra\n",
-      "input_m=(v)*(ia2+ish)\n",
-      "total_loss=input_m-output\n",
-      "cu_loss=ia2**2*ra\n",
-      "cu_loss_f=v*ish\n",
-      "total_cu_loss=cu_loss+cu_loss_f\n",
-      "stray_loss=total_loss-total_cu_loss\n",
-      "stray_loss2=stray_loss*n2/n\n",
-      "cu_loss_a=ia1**2*rt\n",
-      "total_loss2=stray_loss2+cu_loss_f+cu_loss_a\n",
-      "output2=input_m-total_loss2\n",
-      "efficiency=output2*100/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output2,\"W\"\n",
-      "print \"armature current=\",ia2,\"A\"\n",
-      "print \"external resistance=\",r,\"ohm\"\n",
-      "print \"overall efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 4460.66115702 W\n",
-        "armature current= 36.5330578512 A\n",
-        "external resistance= 2.42352222599 ohm\n",
-        "overall efficiency= 52.619059225 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.25, Page Number:1044"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "ia=15.0#A\n",
-      "n=800.0#rpm\n",
-      "ra=0.6#ohm\n",
-      "n2=400.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-ia*ra\n",
-      "r=((v-(n2*eb1/n))/ia)-ra\n",
-      "ia3=ia/2\n",
-      "eb3=v-ia3*(r+ra)\n",
-      "n3=eb3*n/eb1\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 615.584415584 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.26, Page Number:1045"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "r=Symbol('r')\n",
-      "v=400.0#V\n",
-      "inl=3.5#A\n",
-      "il=59.5#A\n",
-      "rf=267.0#ohm\n",
-      "ra=0.2#ohm\n",
-      "vd=2.0#V\n",
-      "ratio=0.02\n",
-      "speed_ratio=0.50\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=inl-ish\n",
-      "eb1=v-ia1*ra-vd\n",
-      "ia2=il-ish\n",
-      "eb2=v-ia2*ra-vd\n",
-      "n1_by_n2=eb1*(1-ratio)/eb2\n",
-      "per_change=(1-1/n1_by_n2)*100\n",
-      "r=solve(eb2*speed_ratio/(eb2-ia2*r)-1,r)\n",
-      "#result\n",
-      "print \"change in speed=\",per_change,\"%\"\n",
-      "print \"resistance to be added=\",r[0],\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "change in speed= 0.83357557339 %\n",
-        "resistance to be added= 3.33092370774547 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaraion\n",
-      "v=200.0#V\n",
-      "i=50.0#A\n",
-      "n=1000.0#rpm\n",
-      "n2=800.0#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=100.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ia2=ia1*(n2/n)**2\n",
-      "eb1=v-ia1*ra\n",
-      "eb2=v-ia2*ra\n",
-      "rt=(v-(n2*eb1/n))/ia2\n",
-      "r=rt-ra\n",
-      "#result\n",
-      "print \"resustance that must be added=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resustance that must be added= 1.32708333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "load=37.3#kW\n",
-      "efficiency=0.90\n",
-      "n=1000#rpm\n",
-      "ra=0.1#ohm\n",
-      "rf=115#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "tsh=9.55*load*1000/n\n",
-      "i=load*1000/(v*efficiency)\n",
-      "ish=v/rf\n",
-      "ia=i-ish\n",
-      "eb=v-ia*ra\n",
-      "ta=9.55*eb*ia/n\n",
-      "i_permissible=i*ratio\n",
-      "ia_per=i_permissible-ish\n",
-      "ra_total=v/ia_per\n",
-      "r_required=ra_total-ra\n",
-      "torque=ratio*ta\n",
-      "#result\n",
-      "print \"net torque=\",ta,\"N-m\"\n",
-      "print \"starting resistance=\",r_required,\"ohm\"\n",
-      "print \"torque developed at starting=\",torque,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "net torque= 365.403326173 N-m\n",
-        "starting resistance= 0.913513513514 ohm\n",
-        "torque developed at starting= 548.104989259 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.29, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "I=Symbol('I')\n",
-      "v=200.0#V\n",
-      "rf=40.0#ohm\n",
-      "ra=0.02#ohm\n",
-      "i=55.0#A\n",
-      "n=595.0#rpm\n",
-      "r=0.58#ohm\n",
-      "n2=630.0#rpm\n",
-      "ia_=15.0#A\n",
-      "rd=5.0#ohm\n",
-      "ia2=50.0#A\n",
-      "\n",
-      "#calculation\n",
-      "ish=v/rf\n",
-      "ia1=i-ish\n",
-      "ra1=r+ra\n",
-      "eb1=v-ra1*ia1\n",
-      "ia2=ia1\n",
-      "eb2=eb1*(n2/n)\n",
-      "r=(v-eb2)/ia1\n",
-      "eb2_=v-ia_*ra1\n",
-      "n2=eb2_*n/eb1\n",
-      "eb3=eb1\n",
-      "IR=v-eb3-ia2*ra\n",
-      "pd=v-IR\n",
-      "i_d=pd/rd\n",
-      "i=ia2+i_d\n",
-      "R=IR/i\n",
-      "I=solve(rd*(I-ia_)-v+R*I,I)\n",
-      "eb4=v-R*I[0]-ia_*ra\n",
-      "n4=n*(eb4/eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"armature circuit resistance should be reduced by=\",ra1-r,\"ohm\"\n",
-      "print \"speed when Ia=\",n2,\"rpm\"\n",
-      "print \"value of series resistance=\",R,\"ohm\"\n",
-      "print \"speed when motor current falls to 15A=\",n4,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature circuit resistance should be reduced by= 0.2 ohm\n",
-        "speed when Ia= 668.5 rpm\n",
-        "value of series resistance= 0.344418052257 ohm\n",
-        "speed when motor current falls to 15A= 636.922222222222 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.31, Page Number:1051"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=15#A\n",
-      "n=600#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=math.sqrt(2*2**0.5*i**2)\n",
-      "n2=n*2*i/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"current=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 713.524269002 rpm\n",
-        "current= 25.2268924576 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.32, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=707#rpm\n",
-      "ia1=100#A\n",
-      "v=85#V\n",
-      "rf=0.03#ohm\n",
-      "ra=0.04#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ra_total=ra+(2*rf)\n",
-      "eb1=v-ia1*ra_total\n",
-      "ia2=ia1*2**0.5\n",
-      "rf=rf/2\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=n*(eb2/eb1)*(2*ia1/ia2)\n",
-      "rt=(v-((n/n2)*eb2))/ia2\n",
-      "r=rt-ra-rf\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1029.46885374 rpm\n",
-        "additional resistance= 0.171040764009 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 44
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.33, Page Number:1052"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varable declaration\n",
-      "v=240.0#V\n",
-      "ia=40.0#A\n",
-      "ra=0.3#ohm\n",
-      "n=1500.0#rpm\n",
-      "n2=1000.0#rpm\n",
-      "#calculation\n",
-      "R=v/ia-ra\n",
-      "eb1=v-ia*ra\n",
-      "r=(v-((n2/n)*eb1))/ia-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added at starting=\",R,\"ohm\"\n",
-      "print \"resistance to be added at 1000 rpm\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added at starting= 5.7 ohm\n",
-        "resistance to be added at 1000 rpm 1.9 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.34, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=600.0#rpm\n",
-      "v=250.0#V\n",
-      "ia1=20.0#A\n",
-      "ratio=2.0\n",
-      "\n",
-      "#calculations\n",
-      "ia2=ia1*2**(3.0/4.0)\n",
-      "n2=n*ratio*ia1/ia2\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",ia2,\"A\"\n",
-      "print \"speed=\",n2,\"rpm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 33.6358566101 A\n",
-        "speed= 713.524269002 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.35, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "V=Symbol('V')\n",
-      "ra=1.0#ohm\n",
-      "v=220.0#V\n",
-      "n=350.0#rpm\n",
-      "ia=25.0#A\n",
-      "n2=500.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ia2=ia*(n2/n)\n",
-      "eb1=v-ia*ra\n",
-      "V=solve((n2*eb1*ia2/(n*ia))+ia2-V,V)\n",
-      "\n",
-      "#result\n",
-      "print \" current=\",ia2,\"A\"\n",
-      "print \"voltage=\",V[0],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " current= 35.7142857143 A\n",
-        "voltage= 433.673469387755 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.36, Page Number:1053"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000.0#rpm\n",
-      "ia=20.0#A\n",
-      "v=200.0#V\n",
-      "ra=0.5#ohm\n",
-      "rf=0.2#ohm\n",
-      "i=20.0#A\n",
-      "rd=0.2#ohm\n",
-      "i_f=10.0#A\n",
-      "ratio=0.70\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-(ra+rf)*ia\n",
-      "r_total=ra+rf/2\n",
-      "eb2=v-r_total*ia\n",
-      "n2=(eb2*n/(eb1*ratio))\n",
-      "    \n",
-      "#result\n",
-      "print \"speed=\",round(n2),\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1444.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.37, Page Number:1054"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200.0#V\n",
-      "ia=40.0#A\n",
-      "n=700.0#rpm\n",
-      "ratio=0.50+1\n",
-      "ra=0.15#ohm\n",
-      "rf=0.1#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ia2=(ratio*2*ia**2)**0.5\n",
-      "eb1=v-ia*(ra+rf)\n",
-      "eb2=v-ia2*(ra+rf)\n",
-      "n2=(eb2/eb1)*(ia*2/ia2)*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\"\n",
-      "print \"speed=\",ia2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 777.147765122 rpm\n",
-        "speed= 69.2820323028 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 63
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.38, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250#V\n",
-      "ia=20#A\n",
-      "n=900#rpm\n",
-      "r=0.025#ohm\n",
-      "ra=0.1#ohm\n",
-      "rd=0.2#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#when divertor is added\n",
-      "eb1=v-ia*(ra+4*r)\n",
-      "ia2=(ia**2*(ra+rd)/rd)**0.5\n",
-      "ra_=rd*ra/(ra+rd)\n",
-      "eb2=v-ia2*ra_\n",
-      "n2=(eb2/eb1)*(ia*3/(2*ia2))*n\n",
-      "\n",
-      "#rearranged field coils in two series and parallel group\n",
-      "ia2=(ia**2*2)**0.5\n",
-      "r=ra+r\n",
-      "eb2=v-ia2*r\n",
-      "n2_=(eb2/eb1)*(ia*2/(ia2))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed when divertor was added=\",n2,\"rpm\"\n",
-      "print \"speed when field coils are rearranged=\",n2_,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed when divertor was added= 1112.87640676 rpm\n",
-        "speed when field coils are rearranged= 1275.19533144 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.39, Page Number:1055"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "n=1000.0#rpm\n",
-      "i=12.0#A\n",
-      "rf=0.8#ohm\n",
-      "ra=1.0#ohm\n",
-      "il=20#A\n",
-      "ratio=0.15\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*(ra+rf)\n",
-      "eb2=v-il*(ra+rf/4)\n",
-      "n2=(eb2/eb1)*(1/(1-ratio))*n\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1162.92198261 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.40, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=200.0#v\n",
-      "n=500.0#rpm\n",
-      "i=25.0#A\n",
-      "ra=0.2#ohm\n",
-      "rf=0.6#ohm\n",
-      "rd=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "r=ra+rf\n",
-      "eb1=v-i*r\n",
-      "i2=solve(((rd+rf)*i2**2)-(v*i2)-(i**2*rd),i2)\n",
-      "pd=v-i2[1]*rf\n",
-      "ia2=((rd+rf)*i2[1]-v)/rd\n",
-      "eb2=pd-ia2*ra\n",
-      "n2=(eb2/eb1)*(i/i2[1])*n\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 342.848235418389 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.41, Page Number:1056"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "ra=0.3#ohm\n",
-      "i=20#A\n",
-      "n=1200#rpm\n",
-      "r=3#ohm\n",
-      "i2=15#A\n",
-      "ratio=0.80\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*ra\n",
-      "eb2=v-(r+ra)*i2\n",
-      "n2=n*(eb2/eb1)/ratio\n",
-      "power_ratio=(n*i)/(n2*i2*ratio)\n",
-      "\n",
-      "#result\n",
-      "print \"new speed=\",n2,\"rpm\"\n",
-      "print \"ratio of power outputs=\",power_ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new speed= 1349.65437788 rpm\n",
-        "ratio of power outputs= 1.48186086214\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.42, Page Number:1057"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=50#A\n",
-      "v=460#V\n",
-      "ratio=1-0.25\n",
-      "\n",
-      "#calculation\n",
-      "I=(i**2*ratio**3)**0.5\n",
-      "eb2=I*ratio*v/i\n",
-      "R=(v-eb2)/I\n",
-      "pa=v*i/1000\n",
-      "power_n=pa*ratio**4\n",
-      "pa=eb2*I\n",
-      "\n",
-      "#result\n",
-      "print \"Resistance required=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Resistance required= 7.26432660412 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.44, Page Number:1060"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=500#rpm\n",
-      "n2=550#rpm\n",
-      "i=50#A\n",
-      "v=500#V\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "eb1=v-i*r\n",
-      "kphi1=eb1/n\n",
-      "eb2=v-i*r\n",
-      "kphi2=eb2/n2\n",
-      "eb_=v-i*2*r\n",
-      "n=eb_/((eb1/n2)+(eb2/n))\n",
-      "#result\n",
-      "print \"speed=\",n,\"rpm\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 248.120300752 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.45, Page Number:1061"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "ratio1=5.0\n",
-      "ratio2=4.0\n",
-      "t=882#N-m\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v\n",
-      "k=v/(n*i/60)\n",
-      "I=(t/((ratio1+ratio2)*0.159*k))**0.5\n",
-      "nsh=v/((ratio1+ratio2)*k*I)\n",
-      "eb1=ratio1*k*I*nsh\n",
-      "eb2=ratio2*k*I*nsh\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",I,\"A\"\n",
-      "print \"speed of shaft=\",round(nsh*60),\"rpm\"\n",
-      "print \"voltage across the motors=\",round(eb1),\"V,\",round(eb2),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 49.5202984449 A\n",
-        "speed of shaft= 134.0 rpm\n",
-        "voltage across the motors= 139.0 V, 111.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 117
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.46, Page Number:1063"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220#V\n",
-      "t=700#N-m\n",
-      "n=1200#rpm\n",
-      "ra=0.008#ohm\n",
-      "rf=55#ohm\n",
-      "efficiency=0.90\n",
-      "t2=375#N-m\n",
-      "n2=1050#rpm\n",
-      "\n",
-      "#calculation\n",
-      "output=2*3.14*n*t/60\n",
-      "power_m=output/efficiency\n",
-      "im=power_m/v\n",
-      "ish=v/rf\n",
-      "ia1=im-ish\n",
-      "eb1=v-ia1*ra\n",
-      "ia2=ia1*t2/t\n",
-      "eb2=eb1*n2/n\n",
-      "r=eb2/ia2-ra\n",
-      "\n",
-      "#result\n",
-      "print \"dynamic break resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "dynamic break resistance= 0.795525014538 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 118
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.47, Page Number:1064"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=18.65#kW\n",
-      "n=450.0#rpm\n",
-      "efficiency=0.746\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(efficiency*v)\n",
-      "eb=v-I*ra\n",
-      "vt=v+eb\n",
-      "i_max=2*I\n",
-      "r=vt/i_max\n",
-      "R=r-ra\n",
-      "N=n/60\n",
-      "phizp_by_a=eb/N\n",
-      "k4=phizp_by_a*v/(2*3.14*r)\n",
-      "k3=phizp_by_a**2/(2*3.14*r)\n",
-      "tb=k4+k3*N\n",
-      "tb0=k4\n",
-      "#result\n",
-      "print \"breaking resistance=\",R,\"ohm\"\n",
-      "print \"maximum breaking torque=\",tb,\"N-m\"\n",
-      "print \"maximum breaking torque when N=0 =\",tb0,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "breaking resistance= 6.1 ohm\n",
-        "maximum breaking torque= 1028.3970276 N-m\n",
-        "maximum breaking torque when N=0 = 522.360394972 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.48, Page Number:1069"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=120#V\n",
-      "ra=0.5#ohm\n",
-      "l=20*0.001#H\n",
-      "ka=0.05#V/rpm motor constant\n",
-      "ia=20#A\n",
-      "\n",
-      "#calculations\n",
-      "vt=ia*ra\n",
-      "alpha=vt/v\n",
-      "#when alpha=1\n",
-      "eb=v-ia*ra\n",
-      "N=eb/ka\n",
-      "\n",
-      "#result\n",
-      "print \"range of speed control=\",0,\"to\",N,\"rpm\"\n",
-      "print \"range of duty cycle=\",(alpha),\"to\",1"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " range of speed control= 0 to 2200.0 rpm\n",
-        "range of duty cycle= 0.0833333333333 to 1\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.49, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=7.46#kW\n",
-      "v=200#V\n",
-      "efficiency=0.85\n",
-      "ra=0.25#ohm\n",
-      "ratio=1.5\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/(v*efficiency)\n",
-      "i1=ratio*i\n",
-      "r1=v/i1\n",
-      "r_start=r1-ra\n",
-      "eb1=v-i*r1\n",
-      "\n",
-      "#result\n",
-      "print \"starting resistance=\",r_start,\"ohm\"\n",
-      "print \"back emf=\",eb1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting resistance= 2.78842716711 ohm\n",
-        "back emf= 66.6666666667 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 125
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.50, Page Number:1080"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "ra=0.5#ohm\n",
-      "ia=40.0#A\n",
-      "n=7\n",
-      "\n",
-      "#calculations\n",
-      "r1=v/ia\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.812 ohm\n",
-        "resistance of 2nd section= 1.215 ohm\n",
-        "resistance of 3rd section= 0.815 ohm\n",
-        "resistance of 4th section= 0.546 ohm\n",
-        "resistance of 5th section= 0.366 ohm\n",
-        "resistance of 6th section= 0.246 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.51, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=6\n",
-      "load=3.73#kW\n",
-      "v=200#V\n",
-      "ratio=0.50\n",
-      "i1=0.6#A\n",
-      "efficiency=0.88\n",
-      "\n",
-      "#calculation\n",
-      "output=load/efficiency\n",
-      "total_loss=output-load\n",
-      "cu_loss=total_loss*ratio\n",
-      "i=output*1000/v\n",
-      "ia=i-i1\n",
-      "ra=cu_loss*1000/ia**2\n",
-      "i_per=i*2\n",
-      "ia_per=i_per-i1\n",
-      "r1=v/ia_per\n",
-      "k=(r1/ra)**(1.0/(n-1))\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-ra\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 1.627 ohm\n",
-        "resistance of 2nd section= 1.074 ohm\n",
-        "resistance of 3rd section= 0.709 ohm\n",
-        "resistance of 4th section= 0.468 ohm\n",
-        "resistance of 5th section= 0.309 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.52, Page Number:1081"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=7\n",
-      "load=36.775#kW\n",
-      "v=400#V\n",
-      "ratio=0.05\n",
-      "rsh=200#ohm\n",
-      "efficiency=0.92\n",
-      "\n",
-      "#calculation\n",
-      "input_m=load*1000/efficiency\n",
-      "cu_loss=input_m*ratio\n",
-      "cu_loss_sh=v**2/rsh\n",
-      "cu_loss_a=cu_loss-cu_loss_sh\n",
-      "i=input_m/v\n",
-      "ish=v/rsh\n",
-      "ia=i-ish\n",
-      "ra=cu_loss_a/ia**2\n",
-      "k=(v/(ia*ra))**(1.0/(n))\n",
-      "i1=k*ia\n",
-      "r1=v/i1\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r5/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.974 ohm\n",
-        "resistance of 2nd section= 0.592 ohm\n",
-        "resistance of 3rd section= 0.36 ohm\n",
-        "resistance of 4th section= 0.219 ohm\n",
-        "resistance of 5th section= 0.133 ohm\n",
-        "resistance of 6th section= 0.0 ohm\n",
-        "resistance of 7th section= 0.081 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.53, Page Number:1082"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=250.0#V\n",
-      "ra=0.125#ohm\n",
-      "i2=150.0#A\n",
-      "i1=200.0#A\n",
-      "\n",
-      "#calculation\n",
-      "r1=v/i1\n",
-      "n=solve((i1/i2)**(n-1)-(r1/ra),n)\n",
-      "k=i1/i2\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "r5=r4/k\n",
-      "r6=r5/k\n",
-      "r7=r6/k\n",
-      "r8=r7/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-r5\n",
-      "p5=r5-r6\n",
-      "p6=r6-r7\n",
-      "p7=r7-r8\n",
-      "p8=r8-ra\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "print \"resistance of 5th section=\",round(p5,3),\"ohm\"\n",
-      "print \"resistance of 6th section=\",round(p6,3),\"ohm\"\n",
-      "print \"resistance of 7th section=\",round(p7,3),\"ohm\"\n",
-      "print \"resistance of 8th section=\",round(p8,3),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 0.313 ohm\n",
-        "resistance of 2nd section= 0.234 ohm\n",
-        "resistance of 3rd section= 0.176 ohm\n",
-        "resistance of 4th section= 0.132 ohm\n",
-        "resistance of 5th section= 0.099 ohm\n",
-        "resistance of 6th section= 0.074 ohm\n",
-        "resistance of 7th section= 0.056 ohm\n",
-        "resistance of 8th section= 0.042 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.54, Page Number:1083"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "n=Symbol('n')\n",
-      "v=500#V\n",
-      "z=20\n",
-      "ra=1.31#ohm\n",
-      "t=218#N-m\n",
-      "ratio=1.5\n",
-      "slot=60\n",
-      "phi=23*0.001#Wb\n",
-      "\n",
-      "#calculation\n",
-      "ia=t/(0.159*phi*slot*z)\n",
-      "i1=ia*ratio\n",
-      "i2=ia\n",
-      "k=i1/i2\n",
-      "r1=v/i1\n",
-      "n=solve(k**(n-1)-(r1/ra),n)\n",
-      "r2=r1/k\n",
-      "r3=r2/k\n",
-      "r4=r3/k\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "p4=r4-ra\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n",
-      "print \"resistance of 4th section=\",round(p4,3),\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of 1st section= 2.237 ohm\n",
-        "resistance of 2nd section= 1.491 ohm\n",
-        "resistance of 3rd section= 0.994 ohm\n",
-        "resistance of 4th section= 0.678 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.55, Page Number:1084"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=37.3#kW\n",
-      "v=440#V\n",
-      "drop=0.02\n",
-      "efficiency=0.95\n",
-      "i_per=1.30\n",
-      "\n",
-      "#calculation\n",
-      "il=load*1000/(v*efficiency)\n",
-      "i1=i_per*il\n",
-      "vd=drop*v\n",
-      "rm=vd/il\n",
-      "r1=v/i1\n",
-      "r=(r1-rm)/6\n",
-      "\n",
-      "#result\n",
-      "print \"resistance of each rheostat=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance of each rheostat= 0.615721729566 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 165
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 30.56, Page Number:1085"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=55.95#kW\n",
-      "v=650.0#V\n",
-      "r=0.51#ohm\n",
-      "i1=140.0#A\n",
-      "i2=100.0#A\n",
-      "per=0.20\n",
-      "\n",
-      "#calculation\n",
-      "ratio=i1/i2\n",
-      "r1=v/i1\n",
-      "r2=((per+1)/ratio-per)*r1\n",
-      "r3=(per+1)*r2/ratio-per*r1\n",
-      "r4=((per+1)*r3/ratio)-per*r1\n",
-      "\n",
-      "p1=r1-r2\n",
-      "p2=r2-r3\n",
-      "p3=r3-r4\n",
-      "\n",
-      "#result\n",
-      "print \"number of steps=\",3\n",
-      "print \"resistance of 1st section=\",round(p1,3),\"ohm\"\n",
-      "print \"resistance of 2nd section=\",round(p2,3),\"ohm\"\n",
-      "print \"resistance of 3rd section=\",round(p3,3),\"ohm\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "number of steps= 3\n",
-        "resistance of 1st section= 1.592 ohm\n",
-        "resistance of 2nd section= 1.364 ohm\n",
-        "resistance of 3rd section= 1.17 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 170
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_1.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_1.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_2.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_2.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_3.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_3.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_4.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_4.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_5.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_5.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_6.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_6.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_7.ipynb
deleted file mode 100755
index 88c66f5b..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter31_7.ipynb
+++ /dev/null
@@ -1,935 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:02fdabadd118404eca71c942f203b8c36bfc89b9baf1e3f2f8e7065ab9807edb"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 31: Testing of DC Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.1, Page Number:1092"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l=38.1#kg\n",
-      "d=63.53*0.01#cm\n",
-      "v=12#rps\n",
-      "i=49#A\n",
-      "V=220#V\n",
-      "\n",
-      "#calculations\n",
-      "r=d/2\n",
-      "torque=l*r*9.81\n",
-      "power=torque*2*3.14*v\n",
-      "motor_input=i*V\n",
-      "efficiency=power*100/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"Output power=\",round(power),\"W\"\n",
-      "print \"Efficiency=\",round(efficiency),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output power= 8947.0 W\n",
-        "Efficiency= 83.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(a), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "spring_b1=10.0#kg\n",
-      "spring_b2=35.0#kg\n",
-      "d=40*0.01#m\n",
-      "v=950.0#rpm\n",
-      "V=200.0#V\n",
-      "i=30.0#A\n",
-      "\n",
-      "#calculations\n",
-      "F=(spring_b2-spring_b1)*9.81\n",
-      "N=v/60\n",
-      "R=d/2\n",
-      "tsh=F*R\n",
-      "omega=2*3.14*N\n",
-      "output=tsh*omega\n",
-      "motor_input=V*i\n",
-      "efficiency=output/motor_input\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 4877.205 W\n",
-        "efficiency= 81.28675 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.2(b), Page Number:1093"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "t1=2.9#kg\n",
-      "t2=0.17#kg\n",
-      "r=7*0.01#m\n",
-      "i=2.0#A\n",
-      "V=230.0#V\n",
-      "n=1500.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "force=(t1-t2)*9.81\n",
-      "torque=force*r\n",
-      "output=torque*2*3.14*n/60\n",
-      "efficiency=output/(V*i)\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",torque,\"N-m\"\n",
-      "print \"output\",output,\"W\"\n",
-      "print \"efficiency\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1.874691 N-m\n",
-        "output 294.326487 W\n",
-        "efficiency 63.984018913 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.3, Page Number:1095"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "V=220.0#V\n",
-      "i=2.5#A\n",
-      "ra=0.8#ohm\n",
-      "rsh=200.0#ohm\n",
-      "I=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_noload=V*i\n",
-      "ish=V/rsh\n",
-      "ia0=i-ish\n",
-      "culoss=ia0**2*ra\n",
-      "constant_loss=input_noload-culoss\n",
-      "ia=32-ish\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "input_=V*I\n",
-      "output=input_-total_loss\n",
-      "efficiency=(output/input_)*100\n",
-      "\n",
-      "#result\n",
-      "print \"Efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Efficiency= 70.1754545455 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.4, Page Number:1096"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "V=400.0#V\n",
-      "i=5.0#A\n",
-      "ra=0.5#ohm\n",
-      "r=200.0#ohm\n",
-      "I=50.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_nl=V*i\n",
-      "ish=V/r\n",
-      "ia=i-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "Ia=I-ish\n",
-      "cu_lossa=Ia**2*ra\n",
-      "total_loss=constant_loss+cu_lossa\n",
-      "input_nl1=V*I\n",
-      "output=input_nl1-total_loss\n",
-      "efficiency=output/input_nl\n",
-      "Eb1=V-(ia*ra)\n",
-      "Eb2=V-(Ia*ra)\n",
-      "change=math.fabs((Eb1-Eb2)/Eb1)\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",output,\"W\"\n",
-      "print \"efficiency=\",efficiency*10,\"%\"\n",
-      "print \"percentage change in speed=\",change*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 16852.5 W\n",
-        "efficiency= 84.2625 %\n",
-        "percentage change in speed= 5.64617314931 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.8, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=200*1000.0#W\n",
-      "v=250.0#V\n",
-      "i1=36.0#A\n",
-      "I1=12.0#A\n",
-      "v1=250.0#V\n",
-      "pd=6.0#V\n",
-      "i2=400.0#A\n",
-      "\n",
-      "#calculations\n",
-      "#no load\n",
-      "ia=i1-I1\n",
-      "ra=pd/i2\n",
-      "cu_loss=ia**2*ra\n",
-      "input_nl=v*i1\n",
-      "constant_loss=input_nl-cu_loss\n",
-      "\n",
-      "#full load\n",
-      "output_i=p/v\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/(p+total_loss)\n",
-      "#result\n",
-      "print \"efficiency at full load=\",efficiency*100,\"%\"\n",
-      "\n",
-      "#half load\n",
-      "output_i=p/(2*v)\n",
-      "ia=output_i+I1\n",
-      "cu_lossa=ia**2*ra\n",
-      "total_loss=cu_lossa+constant_loss\n",
-      "efficiency=p/((p/2+total_loss)*2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at half load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at full load= 91.3736344667 %\n",
-        "efficiency at half load= 89.6559292335 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.9, Page Number:1098"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "p=14.92*1000#W\n",
-      "e=0.88\n",
-      "n=700.0#rpn\n",
-      "rsh=100.0#ohm\n",
-      "i=78.0#A\n",
-      "\n",
-      "#calculations\n",
-      "input_=0.8*p/e\n",
-      "total_loss=input_-0.8*p\n",
-      "input_i=input_/v\n",
-      "ish=v/rsh\n",
-      "ia=input_i-ish\n",
-      "ra=total_loss/(2*(ia**2))\n",
-      "Ia=i-ish\n",
-      "total_loss2=Ia**2*ra+total_loss/2\n",
-      "input__=v*i\n",
-      "efficiency=(input__-total_loss2)*100/input__\n",
-      "Eb1=v-(ia*ra)\n",
-      "Eb2=v-(Ia*ra)\n",
-      "n2=(n*Eb2)/Eb1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"speed=\",n2,\"r.p.m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 86.9450046554 %\n",
-        "speed= 678.443304738 r.p.m\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.10(a), Page Number:1101"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "p=100*1000.0#W\n",
-      "i2=90.0#A\n",
-      "\n",
-      "#calculations\n",
-      "i1=p/v\n",
-      "efficiency=math.sqrt(i1/(i1+i2))*100\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.4 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.11, Page Number:1102"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=15#A\n",
-      "v=200#V\n",
-      "motor_i=100#A\n",
-      "shunt_i1=3#A\n",
-      "shunt_i2=2.5#A\n",
-      "ra=0.05#ohm\n",
-      "cu_loss=500#W\n",
-      "cu_lossa=361#W\n",
-      "ia=85#A\n",
-      "#calculations\n",
-      "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n",
-      "cu_motor=v*shunt_i1\n",
-      "generator_motor=v*shunt_i2\n",
-      "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n",
-      "input_=v*i+cu_motor\n",
-      "output=v*ia*10**(-3)\n",
-      "loss=cu_loss*10**(-3)+1.07+0.36\n",
-      "efficiency=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"eficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eficiency= 89.8045430534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.12, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=110#V\n",
-      "i=48#A\n",
-      "i1=3#a\n",
-      "i2=3.5#A\n",
-      "motor_i=230#A\n",
-      "ra=0.035#ohm\n",
-      "\n",
-      "#calculations\n",
-      "#motor\n",
-      "cu_loss=motor_i**2*ra\n",
-      "brush_loss=motor_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i1\n",
-      "total_cu_lossm=totalarm_culoss+shunt_cu\n",
-      "#generator\n",
-      "arm_i=233-i+i2\n",
-      "cu_loss=arm_i**2*ra\n",
-      "brush_loss=arm_i*2\n",
-      "totalarm_culoss=cu_loss+brush_loss\n",
-      "shunt_cu=v*i2\n",
-      "total_cu_lossg=totalarm_culoss+shunt_cu\n",
-      "#set\n",
-      "totalcu_loss=total_cu_lossm+total_cu_lossg\n",
-      "total_input=v*i\n",
-      "stray_loss=total_input-totalcu_loss\n",
-      "strayloss_per=stray_loss/2\n",
-      "#motor efficiency\n",
-      "input_=233*v\n",
-      "output=input_-(total_cu_lossm+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "print \"motor efficiency=\",e,\"%\"\n",
-      "#generator efficiency\n",
-      "input_=110*185\n",
-      "output=input_-(total_cu_lossg+strayloss_per)\n",
-      "e=output/input_*100\n",
-      "100\n",
-      "print \"generator efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.4590884705 %\n",
-        "generator efficiency= 88.5893642506 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.13, Page Number:1103"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable series\n",
-      "v=500.0#A\n",
-      "p=100*1000.0#w\n",
-      "auxiliary_i=30.0#A\n",
-      "output_i=200.0#A\n",
-      "i1=3.5#A\n",
-      "i2=1.8#A\n",
-      "ra=0.075#ohm\n",
-      "vdb=2.0#V\n",
-      "\n",
-      "#calculations\n",
-      "motor_arm=output_i+auxiliary_i\n",
-      "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n",
-      "motorfield_culoss=v*i2\n",
-      "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n",
-      "generatoefield_culoss=v*i1\n",
-      "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n",
-      "power=v*auxiliary_i\n",
-      "stray_loss=power-total_culoss\n",
-      "permachine=stray_loss/2\n",
-      "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n",
-      "output=v*output_i\n",
-      "e=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 93.1001175389 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.14, Page Number:1104"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "motor_i=400.0#A\n",
-      "i1=6.0#A\n",
-      "i2=5.0#A\n",
-      "ra=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=motor_i**2*ra\n",
-      "generatora_culoss=(motor_i-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*motor_i)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(motor_i-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 92.3148148148 %\n",
-        "generator efficiency 91.4642857143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 77
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.15, Page Number:1105"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "i=50.0#A\n",
-      "ia=380.0#A\n",
-      "i1=5.0#A\n",
-      "i2=4.2#A\n",
-      "ra=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "motora_culoss=ia**2*ra\n",
-      "generatora_culoss=(ia-i)**2*ra\n",
-      "power=v*i\n",
-      "stray_loss=power-(motora_culoss+generatora_culoss)\n",
-      "permachine=stray_loss/2\n",
-      "#motor\n",
-      "total_motor_loss=motora_culoss+(v*i2)+permachine\n",
-      "motor_input=(v*ia)+v*i2\n",
-      "motor_e=(motor_input-total_motor_loss)/motor_input\n",
-      "\n",
-      "#generator\n",
-      "total_gen_loss=generatora_culoss+(v*i1)+permachine\n",
-      "gen_output=v*(ia-i)\n",
-      "gen_e=(gen_output-total_gen_loss)/gen_output\n",
-      "\n",
-      "#result\n",
-      "print \"motor efficiency=\",motor_e*100,\"%\"\n",
-      "print \"generator efficiency\",gen_e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor efficiency= 88.7038001041 %\n",
-        "generator efficiency 95.2121212121 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 81
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.16, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=220.0#V\n",
-      "v2=190.0#V\n",
-      "t=30#sec\n",
-      "t2=20#sec\n",
-      "i=20.0#A\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "avg_i=i/2\n",
-      "power=avg_v*avg_i\n",
-      "W=power*(t2/(t-t2))\n",
-      "\n",
-      "#result\n",
-      "print \"Stray loss=\",W,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Stray loss= 4100.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 85
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.17, Page Number:1107"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "n1=1525.0#rpm\n",
-      "n2=1475.0#ohm\n",
-      "dt=25.0#sec\n",
-      "p=1000.0#W\n",
-      "t2=20.0#sec\n",
-      "\n",
-      "#calculations\n",
-      "N=(n1+n2)/2\n",
-      "w=p*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(w*dt)/((2*3.14/60)**2*N*dN)\n",
-      "\n",
-      "#result\n",
-      "print \"Moment of Inertia=\",I,\"kg-m2\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Moment of Inertia= 121.708791432 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.18, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=240.0#V\n",
-      "v2=225.0#V\n",
-      "dt=25.0#sec\n",
-      "t2=6.0#ohm\n",
-      "iavg=10.0#A\n",
-      "i2=25.0#A\n",
-      "v3=250.0#V\n",
-      "ra=0.4#ohm\n",
-      "r=250.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "avg_v=(v+v2)/2\n",
-      "w_=avg_v*iavg\n",
-      "W=w_*(t2/(dt-t2))\n",
-      "ish=v3/r\n",
-      "ia=i2-ish\n",
-      "cu_loss=ia**2*ra\n",
-      "cu_shunt=v3*ia\n",
-      "total_loss=W+cu_loss+v3\n",
-      "e=((v*i2)-total_loss)/(v*i2)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "734.210526316\n",
-        "efficiency= 79.7564912281 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.19, Page Number:1108"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=1000#rpm\n",
-      "n1=1030#rpm\n",
-      "n2=970#rpm\n",
-      "t1=36#sec\n",
-      "t2=15#sec\n",
-      "t3=9#sec\n",
-      "i=10#A\n",
-      "v=219#V\n",
-      "\n",
-      "#calculations\n",
-      "W=v*i*(t2/(dt-t2))\n",
-      "dN=n1-n2\n",
-      "I=(W*t2)/((2*3.14/60)**2*n*dN)\n",
-      "Wm=W*t2/t1\n",
-      "iron_loss=W-Wm\n",
-      "\n",
-      "#result\n",
-      "print \"i)moment of inertia=\",I,\"kg.m2\"\n",
-      "print \"ii)iron loss=\",iron_loss,\"W\"\n",
-      "print \"iii)mechanical losses=\",Wm,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)moment of inertia= 74.9650087225 kg.m2\n",
-        "ii)iron loss= 1916.25 W\n",
-        "iii)mechanical losses= 1368.75 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 99
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 31.20, Page Number:1110"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "iam=56.0#A\n",
-      "vam=590.0#V\n",
-      "vdm=40.0#V\n",
-      "iag=44.0#A\n",
-      "vag=400.0#V\n",
-      "vdg=40.0#V\n",
-      "r=0.3#ohm\n",
-      "\n",
-      "#calculations\n",
-      "input_total=(vdm+vam)*iam\n",
-      "output=vag*iag\n",
-      "total_loss=input_total-output\n",
-      "rse=vdg/iam\n",
-      "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n",
-      "strayloss=total_loss-cu_loss\n",
-      "permachine=strayloss/2\n",
-      "#motor\n",
-      "inputm=vam*iam\n",
-      "culossm=(r+rse)*iam**2\n",
-      "totallossm=culossm+permachine\n",
-      "output=inputm-totallossm\n",
-      "em=output*100/inputm\n",
-      "#generator\n",
-      "inputg=vag*iag\n",
-      "culossg=(r)*iag**2\n",
-      "totalloss=culossg+permachine+(vdm*iam)\n",
-      "output=vag*iag\n",
-      "eg=output*100/(output+totalloss)\n",
-      "\n",
-      "print \n",
-      "#result\n",
-      "print \"motor efficiency=\",em,\"%\"\n",
-      "print \"generator efficiency=\",eg,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "motor efficiency= 72.6997578692 %\n",
-        "generator efficiency= 67.0220868241 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_1.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_1.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_2.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_2.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_3.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_3.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_4.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_4.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_5.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_5.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_6.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_6.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_7.ipynb
deleted file mode 100755
index a29de087..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter32_7.ipynb
+++ /dev/null
@@ -1,5311 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:69b299b5398cdb7b833f53d6a7d05a19c0a433537449ffb871db80e61817fe5c"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 32: Transformer"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.1, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "phi=1.2#Wb-m2\n",
-      "e=8.0#V\n",
-      "\n",
-      "#calculations\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "a=v2/(4.44*f*n2*phi)\n",
-      "\n",
-      "#result\n",
-      "print \"primary turns=\",n1\n",
-      "print \"secondary turns=\",n2\n",
-      "print \"area of core=\",round(a,2),\"m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary turns= 31.25\n",
-        "secondary turns= 375.0\n",
-        "area of core= 0.03 m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.2, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#KVA\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "f=50#Hz\n",
-      "bm=1.3#Tesla\n",
-      "sf=0.9\n",
-      "per=10#%\n",
-      "a=20*20*sf/10000#m2\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*bm*a)\n",
-      "n2=v2/(4.44*f*bm*a)\n",
-      "e_per_turn=v1/n1\n",
-      "\n",
-      "#result\n",
-      "print \"HV TURNS=\",round(n1)\n",
-      "print \"LV TURNS=\",round(n2)\n",
-      "print \"EMF per turns=\",round(e_per_turn,1),\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV TURNS= 1059.0\n",
-        "LV TURNS= 53.0\n",
-        "EMF per turns= 10.4 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.3, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=400.0\n",
-      "n2=1000.0\n",
-      "a=60.0/10000.0#cm2\n",
-      "f=50.0#Hz\n",
-      "e1=520.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "e2=k*e1\n",
-      "bm=e1/(4.44*f*n1*a)\n",
-      "\n",
-      "#result\n",
-      "print \"peak value of flux density=\",bm,\"WB/m2\"\n",
-      "print \"voltage induced in the secondary winding=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak value of flux density= 0.975975975976 WB/m2\n",
-        "voltage induced in the secondary winding= 1300.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.4, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "n1=500.0\n",
-      "n2=50.0\n",
-      "v=3000.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i1=load*1000/v\n",
-      "i2=i1/k\n",
-      "e1=v/n1\n",
-      "e2=e1*n2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"primary and secondary currents=\",i1,\"A\", i2,\"A\"\n",
-      "print \"secondary emf=\",e2,\"V\"\n",
-      "print \"flux=\",phim*1000,\"mWB\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary and secondary currents= 8.33333333333 A 83.3333333333 A\n",
-        "secondary emf= 300.0 V\n",
-        "flux= 27.027027027 mWB\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.5, Page Number:1123"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11000#V\n",
-      "v2=550#V\n",
-      "load=300#kVA\n",
-      "phim=0.05#Wb\n",
-      "\n",
-      "#calculation\n",
-      "e=4.44*f*phim\n",
-      "e2=v2/1.732\n",
-      "t1=v1/e\n",
-      "t2=e2/e\n",
-      "output=load/3\n",
-      "HV=100*1000/v1\n",
-      "LV=100*1000/e2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",t1\n",
-      "print \"LV turns=\",t2\n",
-      "print \"emf per turn=\",e2\n",
-      "print \"full load HV=\",HV\n",
-      "print \"full load LV=\",LV"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 990.990990991\n",
-        "LV turns= 28.6082849593\n",
-        "emf per turn= 317.551963048\n",
-        "full load HV= 9\n",
-        "full load LV= 314.909090909\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.6, Page Number:1124"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=1200.0\n",
-      "a=80.0/10000.0#m2\n",
-      "f=50.0#Hz\n",
-      "v=500.0#V\n",
-      "\n",
-      "#calculation\n",
-      "phim=n1/(4.44*f*n1)\n",
-      "bm=phim/a\n",
-      "v2=n2*v/n1\n",
-      "\n",
-      "#result\n",
-      "print \"peak flux-density=\",bm,\"Wb\"\n",
-      "print \"voltage induced in the secondary=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "peak flux-density= 0.563063063063 Wb\n",
-        "voltage induced in the secondary= 1200.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.7, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#varible declaration\n",
-      "load=25.0#kVA\n",
-      "n1=250.0\n",
-      "n2=40.0\n",
-      "v=1500.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "v2=n2*v/n1\n",
-      "i1=load*1000/v\n",
-      "i2=load*1000/v2\n",
-      "phim=v/(4.44*f*n1)\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current an secondary current=\",i1,\"A\",i2,\"A\"\n",
-      "print \"ii)seconary emf=\",v2,\"V\"\n",
-      "print \"iii)maximum flux=\",phim*1000,\"mWb\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current an secondary current= 16.6666666667 A 104.166666667 A\n",
-        "ii)seconary emf= 240.0 V\n",
-        "iii)maximum flux= 27.027027027 mWb\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.8, Page Number:1125"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "a=20.0*20.0/10000#m2\n",
-      "phim=1.0#Wbm2\n",
-      "v1=3000.0#V\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculation\n",
-      "t2=v2/(4.44*f*phim*a)\n",
-      "t1=t2*v1/v2\n",
-      "n1=t1/2\n",
-      "n2=t2/2\n",
-      "\n",
-      "#result\n",
-      "print \"HV turns=\",n1\n",
-      "print \"LV turns=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV turns= 168.918918919\n",
-        "LV turns= 12.3873873874\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.9, Page Number:1126"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=200.0#V\n",
-      "i1=0.6#A\n",
-      "p=400.0#W\n",
-      "v3=250.0#V\n",
-      "i0=0.5#A\n",
-      "pf=0.3\n",
-      "\n",
-      "#calculation\n",
-      "il=p/v1\n",
-      "imu=(i1**2-il**2)**0.5\n",
-      "iw=i0*pf\n",
-      "imu2=(i0**2-iw**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"magnetising currents=\",imu,\"A\"\n",
-      "print \"iron loss current=\",il,\"A\"\n",
-      "print \"magnetising components of no load primary current=\",imu2,\"A\"\n",
-      "print \"working components of no-load primary current=\",iw,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "magnetising currents= 0.571788552492 A\n",
-        "iron loss current= 0.181818181818 A\n",
-        "magnetising components of no load primary current= 0.476969600708 A\n",
-        "working components of no-load primary current= 0.15 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.10, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=500.0\n",
-      "n2=40.0\n",
-      "l=150.0#cm\n",
-      "airgap=0.1#mm\n",
-      "e1=3000.0#V\n",
-      "phim=1.2#Wb/m2\n",
-      "f=50.0#Hz\n",
-      "d=7.8#grma/cm3\n",
-      "loss=2.0#watt/kg\n",
-      "\n",
-      "#calculation\n",
-      "a=e1/(4.44*f*n1*phim)\n",
-      "k=n2/n1\n",
-      "v2=k*e1\n",
-      "iron=l*5\n",
-      "air=phim*airgap/(1000*4*3.14*10**(-7))\n",
-      "bmax=iron+air\n",
-      "imu=bmax/(n1*2**0.5)\n",
-      "volume=l*a\n",
-      "im=volume*d*10\n",
-      "total_i=im*2\n",
-      "iw=total_i/(e1)\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "pf=iw/i0\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross sectional area=\",a*10000,\"cm2\"\n",
-      "print \"b)no load secondary voltage=\",v2,\"V\"\n",
-      "print \"c)no load current=\",imu,\"A\"\n",
-      "print \"d)power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross sectional area= 225.225225225 cm2\n",
-        "b)no load secondary voltage= 240.0 V\n",
-        "c)no load current= 1.19577611723 A\n",
-        "d)power factor= 0.145353269536\n"
-       ]
-      }
-     ],
-     "prompt_number": 42
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.11, Page Number:1127"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "n1=1000\n",
-      "n2=200\n",
-      "i=3#A\n",
-      "pf=0.2\n",
-      "i2=280#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "phi1=math.acos(pf2)\n",
-      "i2_=i2/5\n",
-      "phi2=math.acos(pf)\n",
-      "sinphi=math.sin(phi2)\n",
-      "sinphi2=math.sin(math.acos(phi1))\n",
-      "i1=i*complex(pf,-sinphi)+i2_*complex(pf2,-sinphi2)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",abs(i1),\"/_\",math.degrees(phi1),\"degrees\"\n",
-      "\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 64.4918252531 /_ 36.8698976458 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.12, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=440.0#v\n",
-      "v2=110.0#V\n",
-      "i0=5.0#A\n",
-      "pf=0.2\n",
-      "i2=120.0#A\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculation\n",
-      "phi2=math.acos(pf2)\n",
-      "phi0=math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=k*i2\n",
-      "angle=phi2-phi0\n",
-      "i1=(i0**2+i2_**2+(2*i0*i2_*math.cos(angle)))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"current taken by the primary=\",i1,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current taken by the primary= 33.9022604184 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.13, Page Number:1130"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n1=800.0\n",
-      "n2=200.0\n",
-      "pf=0.8\n",
-      "i1=25.0#A\n",
-      "pf2=0.707\n",
-      "i2=80.0#A\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "i2_=i2*k\n",
-      "phi2=math.acos(pf)\n",
-      "phi1=math.acos(pf2)\n",
-      "i0pf2=i1*pf2-i2_*pf\n",
-      "i0sinphi=i1*pf2-i2_*math.sin(math.acos(pf))\n",
-      "phi0=math.atan(i0sinphi/i0pf2)\n",
-      "i0=i0sinphi/math.sin(phi0)\n",
-      "\n",
-      "#result\n",
-      "print \"no load current=\",i0,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load current= 5.91703050525 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.14, Page Number:1131"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=10#A\n",
-      "pf=0.2\n",
-      "ratio=4\n",
-      "i2=200#A\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "phi0=math.acos(pf)\n",
-      "phil=math.acos(pf)\n",
-      "i0=complex(2,-9.8)\n",
-      "i2_=complex(42.5,-26.35)\n",
-      "i1=i0+i2_\n",
-      "phi=math.acos(i1.real/57.333)\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"power factor=\",math.degrees(phi),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= (44.5-36.15j) A\n",
-        "power factor= 39.0890154959 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.15, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable decaration\n",
-      "load=30.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=120.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.1#ohm\n",
-      "x1=0.22#ohm\n",
-      "r2=0.034#ohm\n",
-      "x2=0.012#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "r02=r2+r1*k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"high voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"low voltage side:\"\n",
-      "print \"equivalent winding resistance=\",r02,\"ohm\"\n",
-      "print \"reactance=\",x02,\"ohm\"\n",
-      "print \"impedence=\",z02,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "high voltage side:\n",
-        "equivalent winding resistance= 13.7 ohm\n",
-        "reactance= 5.02 ohm\n",
-        "impedence= 14.5907642021 ohm\n",
-        "low voltage side:\n",
-        "equivalent winding resistance= 0.03425 ohm\n",
-        "reactance= 0.01255 ohm\n",
-        "impedence= 0.0364769105051 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.16, Page Number:1136"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=4400.0#V\n",
-      "v2=220.0#V\n",
-      "r1=3.45#ohm\n",
-      "r2=0.009#ohm\n",
-      "x1=5.2#ohm\n",
-      "x2=0.015#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "r02=r2+k**2*r1\n",
-      "x01=x1+x2/k**2\n",
-      "x02=x2+x1*k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "z02=(r02**2+x02**2)**0.5\n",
-      "cu_loss=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"i)resistance=\"\n",
-      "print \"primary=\",r01,\"ohm\"\n",
-      "print \"secondary=\",r02,\"ohm\"\n",
-      "print \"iii)reactance=\"\n",
-      "print \"primary=\",x01,\"ohm\"\n",
-      "print \"secondary=\",x02,\"ohm\"\n",
-      "print \"iv)impedence=\"\n",
-      "print \"primary=\",z01,\"ohm\"\n",
-      "print \"secondary=\",z02,\"ohm\"\n",
-      "print \"v)copper loss=\",cu_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance=\n",
-        "primary= 7.05 ohm\n",
-        "secondary= 0.017625 ohm\n",
-        "reactance=\n",
-        "primary= 11.2 ohm\n",
-        "secondary= 0.028 ohm\n",
-        "impedence=\n",
-        "primary= 13.2341414531 ohm\n",
-        "secondary= 0.0330853536327 ohm\n",
-        "copper loss= 910.382231405 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.17, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=10.0\n",
-      "load=50.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "f=50.0#Hz\n",
-      "v=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v\n",
-      "z2=v/(i2)\n",
-      "k=v2/v1\n",
-      "z2_=z2/k**2\n",
-      "i2_=k*i2\n",
-      "\n",
-      "#result\n",
-      "print \"a)load impedence=\",z2,\"ohm\"\n",
-      "print \"b)impedence referred to high tension side=\",z2_,\"ohm\"\n",
-      "print \"c)the value of current referred to the high tension side=\",i2_,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)load impedence= 1.152 ohm\n",
-        "b)impedence referred to high tension side= 115.2 ohm\n",
-        "c)the value of current referred to the high tension side= 20.8333333333 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 70
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.18, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "v1=11000.0#V\n",
-      "v2=317.0#V\n",
-      "load2=0.62#kW\n",
-      "lvload=0.48#kW\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "r1=load2*1000/i**2\n",
-      "r2=lvload*1000/i2**2\n",
-      "r2_=r2*k**2\n",
-      "x01=4*v1/(i1*100)\n",
-      "x2_=x01*r2_/(r1+r2_)\n",
-      "x1=x01-x2_\n",
-      "x2=x2_*10/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"i)r1=\",r1,\"ohm\"\n",
-      "print \"r2=\",r2,\"ohm\"\n",
-      "print \"r2_=\",r2_,\"ohm\"\n",
-      "print \"ii)reactance=\",x01,\"ohm\"\n",
-      "print \"x1=\",x1,\"ohm\"\n",
-      "print \"x2=\",x2,\"ohm\"\n",
-      "print \"x2_=\",x2_,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)r1= 7.502 ohm\n",
-        "r2= 0.004823472 ohm\n",
-        "r2_= 5.808 ohm\n",
-        "ii)reactance= 48.4 ohm\n",
-        "x1= 27.28 ohm\n",
-        "x2= 0.175398981818 ohm\n",
-        "x2_= 21.12 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 76
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.19, Page Number:1137"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "k=19.5\n",
-      "r1=25.0#ohm\n",
-      "x1=100.0#ohm\n",
-      "r2=0.06#ohm\n",
-      "x2=0.25#ohm\n",
-      "i=1.25#A\n",
-      "angle=30#degrees\n",
-      "i2=200#A\n",
-      "v=50#V\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v2=complex(500,0)\n",
-      "i2=i2*complex(0.8,-0.6)\n",
-      "z2=complex(r2,x2)\n",
-      "e2=v2+i2*z2\n",
-      "beta=math.atan(e2.imag/e2.real)\n",
-      "e1=e2*k\n",
-      "i2_=i2/k\n",
-      "angle=beta+math.radians(90)+math.radians(angle)\n",
-      "i0=i*complex(math.cos(angle),math.sin(angle))\n",
-      "i1=-i2_+i0\n",
-      "v2=-e1+i1*complex(r1,x1)\n",
-      "phi=math.atan(v2.imag/v2.real)-math.atan(i1.imag/i1.real)\n",
-      "pf=math.cos(phi)\n",
-      "power=abs(v2)*i*math.cos(math.radians(60))\n",
-      "r02=r2+r1/k**2\n",
-      "cu_loss=abs(i2)**2*r02\n",
-      "output=500*abs(i2)*pf2\n",
-      "loss=cu_loss+power\n",
-      "inpt=output+loss\n",
-      "efficiency=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"primary applied voltage=\",v2,\"V\"\n",
-      "print \"primary pf=\",pf\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary applied voltage= (-11464.2126901-1349.15424294j) V\n",
-        "primary pf= 0.698572087114\n",
-        "efficiency= 86.7261056254 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 94
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.20, Page Number:1138"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "load=100#KVA\n",
-      "v1=1100#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "zh=complex(0.1,0.4)\n",
-      "zl=complex(0.006,0.015)\n",
-      "\n",
-      "#calculations\n",
-      "k=v1/v2\n",
-      "#HV \n",
-      "r1=zh.real+zl.real*k**2\n",
-      "x1=zh.imag+zl.imag*k**2\n",
-      "z1=(r1**2+x1**2)**0.5\n",
-      "#LV\n",
-      "r2=r1/k**2\n",
-      "x2=x1/k**2\n",
-      "z2=z1/k**2\n",
-      "\n",
-      "#result\n",
-      "print \"HV:\"\n",
-      "print \"resistance=\",r1,\"ohm\"\n",
-      "print \"reactance=\",x1,\"ohm\"\n",
-      "print \"impedence=\",z1,\"ohm\"\n",
-      "print \"LV:\"\n",
-      "print \"resistance=\",r2,\"ohm\"\n",
-      "print \"reactance=\",x2,\"ohm\"\n",
-      "print \"impedence=\",z2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "HV:\n",
-        "resistance= 0.25 ohm\n",
-        "reactance= 0.775 ohm\n",
-        "impedence= 0.814324873745 ohm\n",
-        "LV:\n",
-        "resistance= 0.01 ohm\n",
-        "reactance= 0.031 ohm\n",
-        "impedence= 0.0325729949498 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.21, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230#V\n",
-      "v2=460#V\n",
-      "r1=0.2#ohm\n",
-      "x1=0.5#ohm\n",
-      "r2=0.75#ohm\n",
-      "x2=1.8#ohm\n",
-      "i=10#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "x02=x2+k**2*x1\n",
-      "vd=i*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "vt2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"secondary terminal voltage=\",vt2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary terminal voltage= 424.8 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.22, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.0#%\n",
-      "x=5.0#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "mu=r*pf+x*math.sin(math.acos(pf))\n",
-      "mu2=r**2+x*0\n",
-      "mu3=r*pf-x*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation at pf=0.8 lag:\",mu,\"%\"\n",
-      "print \"regulation at pf=1:\",mu2,\"%\"\n",
-      "print \"regulation at pf=0.8 lead:\",mu3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=0.8 lag: 3.8 %\n",
-        "regulation at pf=1: 1.0 %\n",
-        "regulation at pf=0.8 lead: -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 98
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.23, Page Number:1141"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=5#%\n",
-      "r=2.5#%\n",
-      "\n",
-      "#calculation\n",
-      "phi=math.atan(x/r)\n",
-      "cosphi=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "regn=r*cosphi+x*sinphi\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.59016994375 %\n",
-        "pf= 0.4472135955\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.24, Page Number:1142"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=2.5#%\n",
-      "x=5#%\n",
-      "load1=500#KVA\n",
-      "load2=400#KVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "kw=load2*pf\n",
-      "kvar=load2*math.sin(math.acos(pf))\n",
-      "drop=(r*kw/load1)+(x*kvar/load1)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage voltage drop=\",drop,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage voltage drop= 4.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 102
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.26, Page Number:1145"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=600#V\n",
-      "v2=1080#V\n",
-      "v=720#V\n",
-      "load=8#W\n",
-      "load2=10#kVA\n",
-      "\n",
-      "#calculation\n",
-      "ir2=load*1000/v2\n",
-      "il2=load*1000/v\n",
-      "ir2_=ir2*v2/v1\n",
-      "il2_=il2*v/v1\n",
-      "ir2=math.sqrt(ir2_**2+il2_**2)\n",
-      "s=complex(load,load2)\n",
-      "s=abs(s)\n",
-      "pf=load/s\n",
-      "i=s*load2*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 21.3437474581 A\n",
-        "power factor= 0.624695047554\n"
-       ]
-      }
-     ],
-     "prompt_number": 103
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.27, Page Number:1046"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "v1=110#V\n",
-      "i=0.5#A\n",
-      "p=30#W\n",
-      "r=0.6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ratio=v/v1\n",
-      "pf=p/(i*v)\n",
-      "sinphi=math.sqrt(1-pf**2)\n",
-      "ip=i*sinphi\n",
-      "iw=i*pf\n",
-      "cu_loss=i**2*r\n",
-      "iron_loss=p-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"i)turns ratio=\",ratio\n",
-      "print \"ii)magnetising component of no-load current=\",ip,\"A\"\n",
-      "print \"iii)working component of no-load current=\",iw,\"A\"\n",
-      "print \"iv)the iron loss=\",iron_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)turns ratio= 2\n",
-        "ii)magnetising component of no-load current= 0.481045692921 A\n",
-        "iii)working component of no-load current= 0.136363636364 A\n",
-        "iv)the iron loss= 29.85 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 104
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.28, Page Number:1047"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=1000.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=2000.0#V\n",
-      "io=1.2#A\n",
-      "po=90.0#W\n",
-      "vs=50.0#V\n",
-      "i_s=5.0#A\n",
-      "ps=110.0#W\n",
-      "p=3.0#kW\n",
-      "pf=0.8\n",
-      "v=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "r0=v**2/po\n",
-      "ia0=v/r0\n",
-      "ip=math.sqrt(io**2-ia0**2)\n",
-      "xm=v/ip\n",
-      "z=vs/i_s\n",
-      "r=ps/25\n",
-      "x=math.sqrt(z**2-r**2)\n",
-      "r1=r*(v1/v2)**2\n",
-      "x1=x*(v1/v2)**2\n",
-      "i_lv1=load*1000/v\n",
-      "i_lv=(p*1000/pf)/v\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "reg=i_lv*(r1*pf+x1*sinphi)/v\n",
-      "vt=v2-reg*1000/v\n",
-      "\n",
-      "#result\n",
-      "print \"LV crrent at rated load=\",i_lv1,\"A\"\n",
-      "print \"LV current at 3kW at 0.8 lagging pf\",i_lv,\"A\"\n",
-      "print \"output secondary voltage=\",vt,\"V\"\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "LV crrent at rated load= 25.0 A\n",
-        "LV current at 3kW at 0.8 lagging pf 18.75 A\n",
-        "output secondary voltage= 999.832975251 V\n",
-        "percentage regulation= 3.34049498886 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 105
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.29, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "loss1=52.0#W\n",
-      "f1=40.0#Hz\n",
-      "loss2=90.0#W\n",
-      "f2=60.0#Hz\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(loss1/f1)-(A+f1*B),(loss2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 45.0 W\n",
-        "eddy current= 25.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.30, Page Number:1048"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "m=10#kg\n",
-      "f=50.0#Hz\n",
-      "f1=25.0\n",
-      "f2=40.0\n",
-      "f3=50.0\n",
-      "f4=60.0\n",
-      "f5=80.0\n",
-      "l1=18.5/f1\n",
-      "l2=36.0/f2\n",
-      "l3=50.0/f3\n",
-      "l4=66.0/f4\n",
-      "l5=104.0/f5\n",
-      "#calculation\n",
-      "ans=solve([l1/f1-(A+f1*B),l2/f2-(A+f2*B)],[A,B])\n",
-      "eddy_loss_per_kg=ans[B]*f**2/m\n",
-      "\n",
-      "#result\n",
-      "print\"eddy current loss per kg at 50 Hz=\",eddy_loss_per_kg,\"W\"\n",
-      "\n",
-      "#plot\n",
-      "F=[f1,f2,f3,f4,f5]\n",
-      "L=[l1,l2,l3,l4,l5]\n",
-      "a=plot(F,L)\n",
-      "xlabel(\"f -->\") \n",
-      "ylabel(\"Wi/f\") \n",
-      "plt.xlim((0,100))\n",
-      "plt.ylim((0.74,2))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Using matplotlib backend: TkAgg\n",
-        "Populating the interactive namespace from numpy and matplotlib\n",
-        "eddy current loss per kg at 50 Hz="
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " -0.118333333333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.31, Page Number:1148"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "A=Symbol('A')\n",
-      "B=Symbol('B')\n",
-      "v1=440#V\n",
-      "f1=50#Hz\n",
-      "p1=2500#W\n",
-      "v2=220#V\n",
-      "f2=25#Hz\n",
-      "p2=850#z\n",
-      "\n",
-      "#calculation\n",
-      "ans=solve([(p1/f1)-(A+f1*B),(p2/f2)-(A+f2*B)],[A,B])\n",
-      "wh=ans[A]*f\n",
-      "we=ans[B]*f**2\n",
-      "\n",
-      "#result\n",
-      "print \"hysteresis=\",round(wh),\"W\"\n",
-      "print \"eddy current=\",round(we),\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "hysteresis= 900.0 W\n",
-        "eddy current= 1600.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.32, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "f1=50.0#Hz\n",
-      "core=1000.0#W\n",
-      "wh=650.0#W\n",
-      "we=350.0#W\n",
-      "v2=2000.0#V\n",
-      "f2=100.0#Hz\n",
-      "\n",
-      "#calculation\n",
-      "a=wh/f1\n",
-      "b=we/f1**2\n",
-      "wh=a*f2\n",
-      "we=b*f2**2\n",
-      "new_core=wh+we\n",
-      "\n",
-      "#result\n",
-      "print \"new core loss=\",new_core,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " new core loss= 2700.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 111
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.33, Page Number:1149"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "phi=1.4#Wb/m2\n",
-      "we=1000.0#W\n",
-      "wh=3000.0#W\n",
-      "per=10.0#%\n",
-      "\n",
-      "#calculation\n",
-      "wh1=wh*1.1**1.6\n",
-      "we1=we*1.1**2\n",
-      "wh2=wh*0.9**(-0.6)\n",
-      "wh3=wh*1.1**1.6*1.1**(-0.6)\n",
-      "#result\n",
-      "print \"a)wh and we when applied voltage is increased by 10%=\",wh1,\"W\",\"and\",we1,\"W\"\n",
-      "print \"b)wh when frequency is reduced by 10%=\",wh2,\"W\"\n",
-      "print \"c)wh and we when both voltage and frequency are increased y 10%=\",wh3,\"W\",\"and\",we1,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)wh and we when applied voltage is increased by 10%= 3494.21441464 W and 1210.0 W\n",
-        "b)wh when frequency is reduced by 10%= 3195.77171838 W\n",
-        "c)wh and we when both voltage and frequency are increased y 10%= 3300.0 W and 1210.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 119
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.34, Page Number:1150"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=40.0#Hz\n",
-      "loss=800.0#W\n",
-      "wh=600.0#W\n",
-      "we=loss-wh\n",
-      "v2=3300.0#V\n",
-      "f2=60.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "a=wh/f\n",
-      "b=we/f**2\n",
-      "core_loss=a*f2+b*f2**2\n",
-      "\n",
-      "#result\n",
-      "print \"core loss at 60 Hz=\",core_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core loss at 60 Hz= 1350.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.35, Page Number:1151"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=30.0#KvA\n",
-      "v1=6000.0#V\n",
-      "v2=230.0#V\n",
-      "r1=10.0#ohm\n",
-      "r2=0.016#ohm\n",
-      "x01=34.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=r1+r2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"primary voltage=\",vsc,\"V\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary voltage= 199.519931911 V\n",
-        "pf= 0.523468222173\n"
-       ]
-      }
-     ],
-     "prompt_number": 124
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.36, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=200.0#V\n",
-      "io=0.7#A\n",
-      "po=70.0#W\n",
-      "vs=15.0#v\n",
-      "i_s=10.0#A\n",
-      "ps=85.0#W\n",
-      "load=5.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cosphi0=po/(vo*io)\n",
-      "sinphi0=math.sin(math.acos(cosphi0))\n",
-      "iw=io*cosphi0\n",
-      "imu=io*sinphi0\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "z02=vs/i_s\n",
-      "k=v2/v1\n",
-      "z01=z02/k**2\n",
-      "r02=ps/i_s**2\n",
-      "r01=r02/k**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "output=load/pf\n",
-      "i2=output*1000/v2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "print z02\n",
-      "#result\n",
-      "print \"secondary voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "1.5\n",
-        "secondary voltage= 377.788243349 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.37, Page Number:1152"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "k=1.0/6\n",
-      "r1=0.9#ohm\n",
-      "x1=5.0#ohm\n",
-      "r2=0.03#ohm\n",
-      "x2=0.13#ohm\n",
-      "vsc=330.0#V\n",
-      "f=50.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=vsc/z01\n",
-      "i2=i1/k\n",
-      "cosphisc=i1**2*r01/(vsc*i1)\n",
-      "\n",
-      "#result\n",
-      "print \"current in low voltage winding=\",i2,\"A\"\n",
-      "print \"pf=\",round(cosphisc,1)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in low voltage winding= 200.396236149 A\n",
-        "pf= 0.2\n"
-       ]
-      }
-     ],
-     "prompt_number": 132
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.38, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "f=50.0#Hz\n",
-      "r1=0.2#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2=0.5#ohm\n",
-      "x2=0.1#ohm\n",
-      "r0=1500.0#ohm\n",
-      "x0=750.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "k=v2/v1\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(iw**2+imu**2)**0.5\n",
-      "pi=v1*iw\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vsc=i1*z01\n",
-      "power=i1**2*r01\n",
-      "\n",
-      "#result\n",
-      "print \"reading of instruments=\",vsc,\"V,\",i1,\"A,\",power,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "reading of instruments= 46.8187996429 V, 20.0 A, 880.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 140
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.39, Page Number:1153"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=1000#kVA\n",
-      "v1=110#V\n",
-      "v2=220#V\n",
-      "f=50#Hz\n",
-      "per1=98.5#%\n",
-      "pf=0.8\n",
-      "per2=98.8#%\n",
-      "\n",
-      "#calculaions\n",
-      "output=load*1\n",
-      "inpt=output*100/per2\n",
-      "loss=inpt-output\n",
-      "inpt_half=(load/2)*pf*100/per1\n",
-      "loss2=inpt_half-400\n",
-      "ans=solve([x+y-loss,(x/4)+y-loss2],[x,y])\n",
-      "kva=load*(ans[y]/ans[x])*0.5\n",
-      "output=kva*1\n",
-      "cu_loss=ans[y]\n",
-      "total_loss=2*cu_loss\n",
-      "efficiency=output/(output+total_loss)\n",
-      "#result\n",
-      "print \"full load copper loss=\",cu_loss,\"kW\"\n",
-      "print \"maximum efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load copper loss= 4.07324441521606 kW\n",
-        "maximum efficiency= 0.968720013059872 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 148
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.40, Page Number:1154"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=200.0#v\n",
-      "v2=400.0#V\n",
-      "r01=0.15#ohm\n",
-      "x01=0.37#ohm\n",
-      "r0=600.0#ohm\n",
-      "x0=300.0#ohm\n",
-      "i2=10.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "imu=v1/x0\n",
-      "iw=v1/r0\n",
-      "i0=(imu**2+iw**2)**0.5\n",
-      "tantheta=iw/imu\n",
-      "theta=math.atan(tantheta)\n",
-      "theta0=math.radians(90)-theta\n",
-      "angle=theta0-math.acos(pf)\n",
-      "k=v2/v1\n",
-      "i2_=i2*k\n",
-      "i1=(i0**2+i2_**2+2*i0*i2_*math.cos(angle))**0.5\n",
-      "r02=k**2*r01\n",
-      "x02=x01*k**2\n",
-      "vd=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)primary current=\",i1,\"A\"\n",
-      "print \"ii)secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)primary current= 20.6693546639 A\n",
-        "ii)secondary terminal voltage= 386.32 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 149
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.43, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "n1=400.0\n",
-      "n2=80.0\n",
-      "r1=0.3#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=1.1#ohm\n",
-      "x2=0.035#ohm\n",
-      "v1=2200.0#V\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=n2/n1\n",
-      "r01=r1+r2/k**2\n",
-      "x01=x1+x2/k**2\n",
-      "z01=complex(r01,x01)\n",
-      "z02=k**2*z01\n",
-      "v2=k*v1\n",
-      "i2=load*1000/v2\n",
-      "vd=i2*(z02.real*pf-z02.imag*math.sin(math.acos(pf)))\n",
-      "regn=vd*100/v2\n",
-      "v2=v2-vd\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent impedence=\",z02,\"ohm\"\n",
-      "print \"ii)voltage regulation=\",regn,\"%\"\n",
-      "print \"secondary terminal voltage=\",v2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent impedence= (0.022+0.079j) ohm\n",
-        "ii)voltage regulation= -1.53925619835 %\n",
-        "secondary terminal voltage= 446.772727273 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.44, Page Number:1158"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "va=450.0#V\n",
-      "vb=120.0#V\n",
-      "v1=120.0#V\n",
-      "i1=4.2#A\n",
-      "w1=80.0#W\n",
-      "v2=9.65#V\n",
-      "i2=22.2#A\n",
-      "w2=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=vb/va\n",
-      "i0=i1*k\n",
-      "cosphi0=w1/(va*i0)\n",
-      "phi0=math.acos(cosphi0)\n",
-      "sinphi0=math.sin(phi0)\n",
-      "iw=i0*cosphi0\n",
-      "imu=i0*sinphi0\n",
-      "r0=va/iw\n",
-      "x0=va/imu\n",
-      "z01=v2/i2\n",
-      "r01=vb/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "loss=w1+w2\n",
-      "output=load*1000*pf\n",
-      "efficiency=output/(output+loss)\n",
-      "iron_loss=w1\n",
-      "cu_loss=(0.5**2)*w2\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "output=load*1000*pf/2\n",
-      "efficiency2=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)equivalent circuit constants=\"\n",
-      "print \"z01=\",z01,\"ohm\"\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r01=\",r01,\"ohm\"\n",
-      "print \"ii)efficiency and voltage regulation at pf=0.8=\",efficiency*100,\"%\",regn,\"%\"\n",
-      "print \"iii)efficiency at half load and pf=0.8=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)equivalent circuit constants=\n",
-        "z01= 0.434684684685 ohm\n",
-        "x01= 0.360090249002 ohm\n",
-        "r01= 0.243486729973 ohm\n",
-        "ii)efficiency and voltage regulation at pf=0.8= 97.5609756098 % 2.02885695496 %\n",
-        "iii)efficiency at half load and pf=0.8= 97.3236009732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.45, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "va=2200.0#V\n",
-      "vb=220.0#V\n",
-      "f=50.0#Hz\n",
-      "v1=220.0#V\n",
-      "i1=4.2#A\n",
-      "w1=148.0#W\n",
-      "v2=86.0#V\n",
-      "i2=10.5#A\n",
-      "w2=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "z01=v2/i2\n",
-      "r01=w2/i2**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/va\n",
-      "drop=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "regn=drop*100/va\n",
-      "pf=r01/z01\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"pf=\",round(pf,1),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 2.94177963326 %\n",
-        "pf= 0.4 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 172
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.46, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=400.0#V\n",
-      "v=60.0#V\n",
-      "i=4.0#A\n",
-      "w=100.0#W\n",
-      "pf=0.8\n",
-      "v_=400.0#V\n",
-      "\n",
-      "#calculations\n",
-      "z01=v/i\n",
-      "r01=w/i**2\n",
-      "x01=(z01**2-r01**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "vd=i1*(r01*pf+x01*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage applied to hv side=\",v1+vd,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage applied to hv side= 2065.90767043 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 182
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.47, Page Number:1159"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=250.0#V\n",
-      "v2=500.0#V\n",
-      "vs=20.0#V\n",
-      "i_s=12.0#A\n",
-      "ws=100.0#W\n",
-      "vo=250.0#V\n",
-      "io=1.0#A\n",
-      "wo=80.0#W\n",
-      "i2=10#A\n",
-      "v2=500#V\n",
-      "pg=0.8\n",
-      "\n",
-      "#calculation\n",
-      "cosphi0=wo/(vo*io)\n",
-      "iw=io*cosphi0\n",
-      "imu=(1-iw**2)**0.5\n",
-      "r0=v1/iw\n",
-      "x0=v1/imu\n",
-      "r02=ws/i_s**2\n",
-      "z02=vs/i_s\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "k=v2/v1\n",
-      "r01=r02/k**2\n",
-      "x01=x02/k**2\n",
-      "z01=z02/k**2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=wo\n",
-      "total_loss=iron_loss+cu_loss\n",
-      "efficiency=i2*v2*pf/(i2*v2*pf+total_loss)\n",
-      "v1_=((vo*pf+x01)**2+(vo*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"applied voltage=\",v1_,\"V\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "applied voltage= 251.442641983 V\n",
-        "efficiency= 96.3984469139 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.48, Page Number:1160"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=230.0#V\n",
-      "v2=230.0#V\n",
-      "load=3.0#kVA\n",
-      "vo=230.0#V\n",
-      "io=2.0#A\n",
-      "wo=100.0#W\n",
-      "vs=15.0#V\n",
-      "i_s=13.0#A\n",
-      "ws=120.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v1\n",
-      "cu_loss=ws\n",
-      "core_loss=wo\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+core_loss)\n",
-      "z=vs/i_s\n",
-      "r=ws/(vs**2)\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=i*(r*pf+x*math.sin(math.acos(pf)))*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 5.90121149256 %\n",
-        "efficiency= 91.6030534351 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 194
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.49, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "efficiency=0.94\n",
-      "per=0.90\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=per*load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "core_loss=loss/2\n",
-      "pc=core_loss/per**2\n",
-      "output=load*1000*pf\n",
-      "cu_loss=pc\n",
-      "efficiency=output/(output+cu_loss+core_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.5728354534 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 196
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.50, Page Number:1161"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=2300.0#V\n",
-      "v2=230.0#V\n",
-      "r1=3.96#ohm\n",
-      "r2=0.0396#ohm\n",
-      "x1=15.8#ohm\n",
-      "x2=0.158#ohm\n",
-      "pf=0.8\n",
-      "v=230.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "r=r2+r1*(v2/v1)**2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "v1_=v2+i*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "v1=v1_*(v1/v2)\n",
-      "phi=math.atan(r/x)\n",
-      "pf=math.cos(phi)\n",
-      "#result\n",
-      "print \"a)HV side voltage necessary=\",v1,\"V\"\n",
-      "print \"b)pf=\",round(pf,2)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)HV side voltage necessary= 2409.9826087 V\n",
-        "b)pf= 0.97\n"
-       ]
-      }
-     ],
-     "prompt_number": 199
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.51, Page Number:1162"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#v\n",
-      "r1=3.4#ohm\n",
-      "x1=7.2#ohm\n",
-      "r2=0.028#ohm\n",
-      "x2=0.060#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "r=r1*(v2/v1)**2+r2\n",
-      "x=x1*(v2/v1)**2+x2\n",
-      "ad=i*r*pf\n",
-      "dc=i*x*math.sin(math.acos(pf))\n",
-      "oc=v2+ad+dc\n",
-      "bd=i*r*math.sin(math.acos(pf))\n",
-      "b_f=x*pf\n",
-      "cf=b_f-bd\n",
-      "v1_=(oc**2+cf**2)**0.5\n",
-      "v1=v1_*(v1/v2)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage on hv side=\",v1,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage on hv side= 2229.28500444 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 200
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.52, Page Number:1163"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "i1=0.7#A\n",
-      "w1=65.0#W\n",
-      "v=15.0#V\n",
-      "i2=10.0#A\n",
-      "w2=75.0#W\n",
-      "pf=0.80\n",
-      "#calculation\n",
-      "il=load*1000/v1\n",
-      "ih=load*1000/v2\n",
-      "cu_loss=w2\n",
-      "constant_loss=w1\n",
-      "z=v/i2\n",
-      "r=w2/i2**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "efficiency=load*100000/(load*1000+cu_loss+constant_loss)\n",
-      "regn=i2*(r*pf+x*math.sin(math.acos(pf)))\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency,\"%\"\n",
-      "print \"full load regulation=\",regn,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.6183574879 %\n",
-        "full load regulation= 13.7942286341 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 209
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.53, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=3300.0#V\n",
-      "v2=230.0#V\n",
-      "load=50.0#kVA\n",
-      "z=4\n",
-      "cu_loss=1.8\n",
-      "\n",
-      "#calculations\n",
-      "x=(z**2-cu_loss**2)**0.5\n",
-      "i1=load*1000/v1\n",
-      "r01=cu_loss*v1/(100*i1)\n",
-      "x01=x*v1/(100*i1)\n",
-      "z01=z*v1/(100*i1)\n",
-      "isc=i1*100/z\n",
-      "print \n",
-      "#result\n",
-      "print \"%x=\",x,\"%\"\n",
-      "print \"resistance=\",r01,\"ohm\"\n",
-      "print \"reactance=\",x01,\"ohm\"\n",
-      "print \"impedence=\",z01,\"ohm\"\n",
-      "print \"primary sc current=\",isc,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "%x= 3.5721142199 %\n",
-        "resistance= 3.9204 ohm\n",
-        "reactance= 7.78006477094 ohm\n",
-        "impedence= 8.712 ohm\n",
-        "primary sc current= 378.787878788 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.54, Page Number:1164"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "vo=220.0#V\n",
-      "i_o=4.2#A\n",
-      "wo=148.0#W\n",
-      "vs=86.0#V\n",
-      "i_s=10.5#A\n",
-      "ws=360.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r01=ws/i_s**2\n",
-      "r02=k**2*r01\n",
-      "z10=vs/i_s\n",
-      "x01=(z10**2-r01**2)**0.5\n",
-      "x02=k**2*x01\n",
-      "i1=load*1000/v1\n",
-      "v1_=((v1*pf+i1*r01)**2+(v1*math.sin(math.acos(pf))+i1*x01)**2)**0.5\n",
-      "regn1=(v1_-v1)/v1\n",
-      "i2=i1/k\n",
-      "core_loss=wo\n",
-      "cu_loss=i1**2*r01\n",
-      "cu_loss_half=(i1/2)**2*r01\n",
-      "efficiency=load*1000*pf*100/(load*1000*pf+core_loss+cu_loss)\n",
-      "efficiency_half=(load/2)*1000*pf*100/((load/2)*1000*pf+core_loss+cu_loss)\n",
-      "print v1_                                  \n",
-      "#result\n",
-      "print \"a)core loss=\",wo,\"W\"\n",
-      "print \"b)equivalent resistance primary=\",r01,\"ohm\"\n",
-      "print \"c)equivalent resistance secondary=\",r02,\"ohm\"\n",
-      "print \"d)equivalent reactance primary=\",x01,\"ohm\"\n",
-      "print \"e)equivalent reactance secondary=\",x02,\"ohm\"\n",
-      "print \"f)regulation=\",regn1*100,\"%\"\n",
-      "print \"g)efficiency at full load=\",efficiency,\"%\"\n",
-      "print \"h)efficiency at half load=\",efficiency_half,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "2265.01840886\n",
-        "a)core loss= 148.0 W\n",
-        "b)equivalent resistance primary= 3.26530612245 ohm\n",
-        "c)equivalent resistance secondary= 0.0326530612245 ohm\n",
-        "d)equivalent reactance primary= 7.51143635755 ohm\n",
-        "e)equivalent reactance secondary= 0.0751143635755 ohm\n",
-        "f)regulation= 2.95538222101 %\n",
-        "g)efficiency at full load= 97.4548448466 %\n",
-        "h)efficiency at half load= 95.0360304208 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 222
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.55, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "er=1.0/100\n",
-      "ex=5.0/100\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "regn2=er*1\n",
-      "regn3=er*pf-ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation with pf=0.8 lag=\",regn*100,\"%\"\n",
-      "print \"ii)regulation with pf=1=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation with pf=0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation with pf=0.8 lag= 3.8 %\n",
-        "ii)regulation with pf=1= 1.0 %\n",
-        "iii)regulation with pf=0.8 lead= -2.2 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.56, Page Number:1165"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500#kVA\n",
-      "v1=3300#V\n",
-      "v2=500#V\n",
-      "f=50#Hz\n",
-      "per=0.97\n",
-      "ratio=3.0/4\n",
-      "zper=0.10\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "output=load*ratio*1\n",
-      "x=0.75\n",
-      "pi=0.5*(output*(1/per-1))\n",
-      "pc=pi/x**2\n",
-      "i1=load*1000/v1\n",
-      "r=pc*1000/i1**2\n",
-      "er=i1*r/v1\n",
-      "ez=zper\n",
-      "ex=(ez**2-er**2)**0.5\n",
-      "regn=er*pf+ex*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"regulation=\",regn*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 7.52529846012 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.57, Page Number:1166"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "cu_loss=1.5#%\n",
-      "xdrop=3.5#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "pur=cu_loss/100\n",
-      "pux=xdrop/100\n",
-      "regn2=pur*pf+pux*math.sin(math.acos(pf))\n",
-      "regn1=pur*1\n",
-      "regn3=pur*pf-pux*math.sin(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"i)regulation at unity pf=\",regn1*100,\"%\"\n",
-      "print \"ii)regulation at 0.8 lag=\",regn2*100,\"%\"\n",
-      "print \"iii)regulation at 0.8 lead=\",regn3*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)regulation at unity pf= 1.5 %\n",
-        "ii)regulation at 0.8 lag= 3.3 %\n",
-        "iii)regulation at 0.8 lead= -0.9 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.58, Page Number:1168"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#KVA\n",
-      "w1=5.0#kW\n",
-      "w2=7.5#kW\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "loss=total_loss/2\n",
-      "cu_loss=efficiency**2*w2/2\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+cu_loss+2.5)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.0186963113 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.59, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2000.0#V\n",
-      "v2=200.0#V\n",
-      "w1=350.0#W\n",
-      "w2=400.0#W\n",
-      "\n",
-      "#calculation\n",
-      "total_loss=w1+w2\n",
-      "output=load*1000*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=w2*(0.5)**2\n",
-      "total_loss=cu_loss+w1\n",
-      "efficiency2=(load*1000/2)/((load*1000/2)+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency at full load=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency at full load= 97.0873786408 %\n",
-        "ii)efficiency at half load= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 232
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.60, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.75\n",
-      "\n",
-      "#calculation\n",
-      "ratio=efficiency**2\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of P1 and P2=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of P1 and P2= 0.5625\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.61, Page Number:1170"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=230.0#V\n",
-      "load1=150.0#KVA\n",
-      "f=50.0#Hz\n",
-      "loss=1.4#kW\n",
-      "cu_loss=1.6#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "load=load1*(cu_loss/loss)**0.5\n",
-      "total_loss=loss*2\n",
-      "output=load*1\n",
-      "efficiency=output/(output+total_loss)\n",
-      "cu_loss=cu_loss*(0.5)**2\n",
-      "total_loss=total_loss+cu_loss\n",
-      "output2=(load/2)*pf\n",
-      "efficiency2=output2/(output2+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load for max efficiency=\",load1,\"kVA\"\n",
-      "print \"max efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)efficiency at half load=\",efficiency2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load for max efficiency= 150.0 kVA\n",
-        "max efficiency= 98.283858876 %\n",
-        "ii)efficiency at half load= 95.2481856352 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 237
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.62, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%pylab\n",
-      "#variable declaration\n",
-      "load=5#kVA\n",
-      "v1=2300#V\n",
-      "v2=230#V\n",
-      "f=50#Hz\n",
-      "iron_loss=40#W\n",
-      "cu_loss=112#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "def e(k):\n",
-      "    e=k*pf*1000*100/(k*pf*1000+(cu_loss*(k/5)**2+40))\n",
-      "    return(e)\n",
-      "\n",
-      "e1=e(1.25)\n",
-      "e2=e(2.5)\n",
-      "e3=e(3.75)\n",
-      "e4=e(5.0)\n",
-      "e5=e(6.25)\n",
-      "e6=e(7.5)\n",
-      "\n",
-      "K=[1.25,2.5,3.75,5.0,6.25,7.5]\n",
-      "E=[e1,e2,e3,e4,e5,e6]\n",
-      "a=plot(K,E)\n",
-      "xlabel(\"load,kVA\") \n",
-      "ylabel(\"Efficiency\") \n",
-      "plt.xlim((0,8))\n",
-      "plt.ylim((92,98))\n",
-      "show(a)\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.63, Page Number:1171"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kVA\n",
-      "efficiency=0.98\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "x=loss*1000/(1+9.0/16)\n",
-      "y=(9.0/16)*x\n",
-      "cu_loss=x*(1.0/2)**2\n",
-      "total_loss=cu_loss+y\n",
-      "output=load*pf*0.5\n",
-      "efficiency=output/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency at hald load=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency at hald load= 97.9216626699 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.64, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=25.0#kVA\n",
-      "v1=2200.0#V\n",
-      "v2=220.0#V\n",
-      "r1=1.0#ohm\n",
-      "r2=0.01#ohm\n",
-      "pf=0.8\n",
-      "loss=0.80\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=r2+k**2*r1\n",
-      "i2=load*1000/v2\n",
-      "cu_loss=i2**2*r02\n",
-      "iron_loss=loss*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "output=load*pf*1000\n",
-      "efficiency=output/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"secondary resistance=\",r02,\"ohm\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary resistance= 0.02 ohm\n",
-        "efficiency= 97.7284199899 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.65, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "r01=0.5#ohm\n",
-      "x01=1.5#ohm\n",
-      "ratio=3.0/4\n",
-      "pf=0.8\n",
-      "v=220.0#V\n",
-      "loss=100.0#W\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=k**2*r01\n",
-      "x02=k**2*x01\n",
-      "i2=1000*load*ratio/v2\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "cu_loss=i2**2*r02\n",
-      "total_loss=loss+cu_loss\n",
-      "output=load*ratio*pf\n",
-      "inpt=output*1000+total_loss\n",
-      "efficiency=output*1000/(inpt)\n",
-      "#result\n",
-      "print \"output=\",output,\"w\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 2.4 w\n",
-        "efficiency= 91.8660287081 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.66, Page Number:1172"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=440.0#V\n",
-      "v2=220.0#V\n",
-      "f=50.0#Hz\n",
-      "loss=324.0#W\n",
-      "cu_loss=100.0#W\n",
-      "pf=0.8\n",
-      "#calculations\n",
-      "cu_loss=4*cu_loss\n",
-      "efficiency=load*pf/(load*pf+cu_loss/1000+loss/1000)\n",
-      "per=(loss/cu_loss)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)efficiency=\",efficiency*100,\"%\"\n",
-      "print \"ii)percent of full-load=\",per*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)efficiency= 95.6708921311 %\n",
-        "ii)percent of full-load= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.67, Page Number:1173"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=4.0#kVA\n",
-      "v1=200.0#V\n",
-      "v2=400.0#V\n",
-      "pf=0.8\n",
-      "vo=200.0#V\n",
-      "io=0.8#A\n",
-      "wo=70.0#W\n",
-      "vs=20.0#V\n",
-      "i_s=10.0#A\n",
-      "ws=60.0#W\n",
-      "\n",
-      "#calculation\n",
-      "i2=load*1000/v2\n",
-      "loss=ws+wo\n",
-      "output=load*pf\n",
-      "efficiency=output/(output+loss/1000)\n",
-      "z02=vs/i_s\n",
-      "r02=ws/i2**2\n",
-      "x02=(z02**2-r02**2)**0.5\n",
-      "drop=i2*(r02*pf+x02*math.sin(math.acos(pf)))\n",
-      "v2=v2-drop\n",
-      "i1=load*1000/v1\n",
-      "load=load*(wo/ws)**0.5\n",
-      "load=load*1\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n",
-      "print \"current=\",i1,\"A\"\n",
-      "print \"load at unity pf=\",load,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.0960960961 %\n",
-        "secondary voltage= 383.752729583 V\n",
-        "current= 20.0 A\n",
-        "load at unity pf= 4.32049379894 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.69, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "x=Symbol('x')\n",
-      "y=Symbol('y')\n",
-      "load=600.0#KVA\n",
-      "efficiency=0.92\n",
-      "per=0.60\n",
-      "\n",
-      "#calculation\n",
-      "inpt=load/efficiency\n",
-      "loss1=inpt-load\n",
-      "inpt2=load/(2*efficiency)\n",
-      "loss2=inpt2-load/2\n",
-      "ans=solve([x+y-loss1,x+y/4-loss2],[x,y])\n",
-      "cu_loss=ans[y]*0.36\n",
-      "loss=cu_loss+ans[x]\n",
-      "output=load*per\n",
-      "efficiency=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "389.913043478261\n",
-        "efficiency= 92.3282783229260 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.70, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "e1=0.98\n",
-      "e2=0.80\n",
-      "pf=8\n",
-      "z=0.05\n",
-      "pf1=0.8\n",
-      "\n",
-      "#calculations\n",
-      "output=load*pf1*e2\n",
-      "inpt=output/e1\n",
-      "loss=-output+inpt\n",
-      "cu_loss=loss/2\n",
-      "cu_loss_full=cu_loss/pf1**2\n",
-      "r=round(cu_loss_full*100/load)\n",
-      "sin=math.sin(math.acos(pf1))\n",
-      "regn=(r*pf1+5*sin)+(1.0/200)*(5*pf1-r*sin)**2\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 3.8578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.71, Page Number:1174"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#KVA\n",
-      "v1=5000.0#V\n",
-      "v2=440.0#V\n",
-      "f=25.0#Hz\n",
-      "cu_loss=1.5\n",
-      "we=0.5\n",
-      "wh=0.6\n",
-      "v2=10000.0\n",
-      "#calculations\n",
-      "cu_loss1=cu_loss*load/100\n",
-      "we1=we*load/100\n",
-      "wh1=wh*load/100\n",
-      "cu_loss2=cu_loss1\n",
-      "we2=(we1*(50.0/25.0)**2)\n",
-      "wh2=(wh1*(50.0/25))\n",
-      "e1=load*100/(load+cu_loss1+we1+wh1)\n",
-      "e2=load*2*100/(load*2+cu_loss2+we2+wh2)\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency in first case=\",e1,\"%\"\n",
-      "print \"full load efficiency in second case=\",e2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "20.47 0.06 0.05\n",
-        "full load efficiency in first case= 97.4658869396 %\n",
-        "full load efficiency in second case= 97.7039570103 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.72, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=300#KVA\n",
-      "r=1.5#%\n",
-      "load1=173.2#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=r*load*1000/100\n",
-      "iron_loss=(load1/load)**2*cu_loss\n",
-      "total_loss=cu_loss+iron_loss\n",
-      "efficiency=(load*pf)*100/((load*pf)+(total_loss/1000))\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.5610105096 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.73, Page Number:1175"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100#kVA\n",
-      "v1=2300#V\n",
-      "v2=230.0#V\n",
-      "f=50#Hz\n",
-      "phim=1.2#Wb/m2\n",
-      "a=0.04#m2\n",
-      "l=2.5#m\n",
-      "bm=1200\n",
-      "inpt=1200#W\n",
-      "pi=400#W\n",
-      "efficiency=0.75\n",
-      "pf=0.8\n",
-      "f2=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "n1=v1/(4.44*f*phim*a)\n",
-      "k=v2/v1\n",
-      "n2=k*n1\n",
-      "i=1989/n1\n",
-      "cu_loss=efficiency**2*inpt\n",
-      "total_loss=pi+cu_loss\n",
-      "output=load*efficiency*pf\n",
-      "efficiency=output*100/(output+total_loss/1000)\n",
-      "\n",
-      "#result\n",
-      "print \"a)n1=\",round(n1)\n",
-      "print \"  n2=\",round(n2)\n",
-      "print \"b)magnetising current=\",i,\"A\"\n",
-      "print \"c)efficiency=\",efficiency,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.00643416423287\n",
-        "a)n1= 216.0\n",
-        "  n2= 22.0\n",
-        "b)magnetising current= 9.21512347826 A\n",
-        "c)efficiency= 98.2398690135 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.74, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=1.8\n",
-      "x=5.4\n",
-      "\n",
-      "#calculation\n",
-      "pf=r/x\n",
-      "phi=math.atan(pf)\n",
-      "phi2=math.atan(x/r)\n",
-      "regn=r*math.cos(phi2)+x*math.sin(phi2)\n",
-      "efficiency=100/(100+r*2)\n",
-      "\n",
-      "#result\n",
-      "print \"a)i)phi=\",math.degrees(phi),\"degrees\"\n",
-      "print \"  ii)regulation=\",regn,\"%\"\n",
-      "print \"b)efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)i)phi= 18.4349488229 degrees\n",
-        "  ii)regulation= 5.6920997883 %\n",
-        "b)efficiency= 96.5250965251 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.75, Page Number:1176"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "f=50.0#Hz\n",
-      "v1=500.0#V\n",
-      "v2=250.0#V\n",
-      "vo=250.0#V\n",
-      "io=3.0#A\n",
-      "wo=200.0#W\n",
-      "vsc=15.0#V\n",
-      "isc=30.0#A\n",
-      "wsc=300.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v2\n",
-      "cu_loss=(i/isc)**2*wsc\n",
-      "output=load*1000*pf\n",
-      "efficiency=output*100/(output+cu_loss+wo)\n",
-      "z=vsc/isc\n",
-      "r=wsc/isc**2\n",
-      "x=(z**2-r**2)**0.5\n",
-      "regn=(i/v2)*(r*pf-x*math.sin(math.acos(pf)))*v2\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 91.6030534351 %\n",
-        "regulation= 1.72239475667 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 64
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.76, Page Number:1177"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40.0#kVA\n",
-      "loss=400.0#W\n",
-      "cu_loss=800.0#W\n",
-      "\n",
-      "#calculation\n",
-      "x=(loss/cu_loss)**0.5\n",
-      "output=load*x*1\n",
-      "efficiency=output/(output+load*2/100)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.2493723732 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.77, Page Number:1178"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#kVA\n",
-      "v1=500#V\n",
-      "v2=250#V\n",
-      "vsc=60#V\n",
-      "isc=20#A\n",
-      "wsc=150#W\n",
-      "per=1.2\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=load*1000/v1\n",
-      "cu_loss=per**2*wsc\n",
-      "output=per*load*1.0\n",
-      "efficiency=output*100/(output+cu_loss*2/1000)\n",
-      "output=load*1000*pf\n",
-      "e2=output*100/(output+cu_loss+wsc)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum efficiency=\",efficiency,\"%\"\n",
-      "print \"full-load efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum efficiency= 96.5250965251 %\n",
-        "full-load efficiency= 95.6251494143 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.78, Page Number:1181"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#kVA\n",
-      "cu_loss=4.5#kW\n",
-      "iron_loss=3.5#kW\n",
-      "t1=6.0#hrs\n",
-      "t2=10.0#hrs\n",
-      "t3=4.0#hrs\n",
-      "t4=4.0#hrs\n",
-      "load1_=400.0#kW\n",
-      "load2_=300.0#kW\n",
-      "load3_=100.0#kW\n",
-      "pf1=0.8\n",
-      "pf2=0.75\n",
-      "pf3=0.8\n",
-      "\n",
-      "#calculations\n",
-      "load1=load1_/pf1\n",
-      "load2=load2_/pf2\n",
-      "load3=load3_/pf3\n",
-      "wc1=cu_loss\n",
-      "wc2=cu_loss*(load2/load1)**2\n",
-      "wc3=cu_loss*(load3/load1)**2\n",
-      "twc=(t1*wc1)+(t2*wc2)+(t3*wc3)+(t4*0)\n",
-      "iron_loss=24*iron_loss\n",
-      "total_loss=twc+iron_loss\n",
-      "output=(t1*load1_)+(t2*load2_)+(t3*load3_)\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",round(efficiency,1),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 86
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.79, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#kVA\n",
-      "loss=3.0#kW\n",
-      "tf=3.0#hrs\n",
-      "th=4.0#hrs\n",
-      "\n",
-      "#calculation\n",
-      "iron_loss=loss*24/2\n",
-      "wcf=loss*tf/2\n",
-      "wch=loss/8\n",
-      "wch=wch*4\n",
-      "total_loss=iron_loss+wch+wcf\n",
-      "output=load*tf+load*th/2\n",
-      "efficiency=output*100/(output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 92.2509225092 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 89
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.80, Page Number:1182"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=100.0#KW\n",
-      "efficiency=0.98\n",
-      "tf=4.0#hrs\n",
-      "th=6.0#hrs\n",
-      "t10=14.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "#1st transformer\n",
-      "inpt=load/efficiency\n",
-      "tloss=inpt-load\n",
-      "y=tloss/2\n",
-      "x=y\n",
-      "iron_loss=x*24\n",
-      "cu_loss=x*tf+th*(x/2**2)+t10*(x/10**2)\n",
-      "loss=iron_loss+cu_loss\n",
-      "output=tf*load+th*load/2+t10*10\n",
-      "e1=output/(output+loss)\n",
-      "#2nd transformer\n",
-      "y=tloss/(1+1.0/4)\n",
-      "x=(tloss-y)\n",
-      "iron_loss=x*24\n",
-      "wc=tf*y+th*(y/2**2)+t10*(y/10**2)\n",
-      "loss=iron_loss+wc\n",
-      "e2=output/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency of forst transformer=\",e1*100,\"%\"\n",
-      "print \"efficiency ofsecond transformer=\",e2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.408163265306 1.63265306122\n",
-        "efficiency of forst transformer= 96.5245532574 %\n",
-        "efficiency ofsecond transformer= 97.7876610788 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.81, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "efficiency=0.95\n",
-      "nl=10.0#hrs\n",
-      "ql=7.0#hrs\n",
-      "hl=5.0#hrs\n",
-      "fl=2.0#hrs\n",
-      "\n",
-      "#calculations\n",
-      "inpt=load/efficiency\n",
-      "loss=inpt-load\n",
-      "wc_fl=loss/2\n",
-      "iron_loss=loss/2\n",
-      "wc_fl_4=(1.0/4)**2*wc_fl\n",
-      "wc_fl_2=(1.0/2)**2*wc_fl\n",
-      "wc_ql=ql*wc_fl_4\n",
-      "wc_hl=hl*wc_fl_2\n",
-      "wc_fl_2=fl*wc_fl\n",
-      "wc=wc_ql+wc_hl+wc_fl_2\n",
-      "wh=wc\n",
-      "loss=wh+24*iron_loss\n",
-      "output=load*1\n",
-      "half_output=(output/2)\n",
-      "q_load=(load/4)\n",
-      "output=ql*q_load+hl*half_output+fl*output\n",
-      "e=output*100/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 89.5592740985 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 115
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.82, Page Number:1183"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.98\n",
-      "load=15#kVA\n",
-      "t1=12.0#hrs\n",
-      "t2=6.0#hrs\n",
-      "t3=6.0#hrs\n",
-      "pf1=0.5\n",
-      "pf2=0.8\n",
-      "k1=2#kW\n",
-      "k2=12#kW\n",
-      "\n",
-      "#calculations\n",
-      "output=load*1\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "wc=loss/2\n",
-      "wi=loss/2\n",
-      "w1=k1/pf1\n",
-      "w2=k2/pf2\n",
-      "wc1=wc*(4/load)\n",
-      "wc2=wc\n",
-      "wc12=t1*wc1\n",
-      "wc6=t2*wc2\n",
-      "wc=(wc12+wc6)\n",
-      "wi=24*wi\n",
-      "output=(k1*t1)+(t2*k2)\n",
-      "inpt=output+wc+wi\n",
-      "e=output*100/inpt\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",e,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.918367346939 3.67346938776\n",
-        "efficiency= 95.4351795496 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.83, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=150.0#KVA\n",
-      "l1_=100.0#kVA\n",
-      "t=3.0#hrs\n",
-      "loss=1.0#KW\n",
-      "\n",
-      "#calculations\n",
-      "l1=l1_/2\n",
-      "l2=l1_\n",
-      "output=load*1\n",
-      "loss=loss*2\n",
-      "e1=output/(output+loss)\n",
-      "wc1=t*(1.0/3)**2*1\n",
-      "wc2=8*(2.0/3)**2*1\n",
-      "wc=wc1+wc2\n",
-      "wi=24*1\n",
-      "loss=wc+wi\n",
-      "output=3*(l1*1)+8*(l2*1)\n",
-      "e2=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"ordinary efficiency=\",e1*100,\"%\"\n",
-      "print \"all day efficiency=\",e2,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ordinary efficiency= 98.6842105263 %\n",
-        "all day efficiency= 97.1480513578 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.84, Page Number:1184"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50#KVA\n",
-      "efficiency=0.94#%\n",
-      "nl=10\n",
-      "hl=5.0\n",
-      "ql=6.0\n",
-      "fl=3.0\n",
-      "\n",
-      "#calculations\n",
-      "pi=0.5*(load*1000)*(1-efficiency)/efficiency\n",
-      "wch=(0.5)**2*pi\n",
-      "eh=wch*hl/1000\n",
-      "wcq=(0.25)**2*pi\n",
-      "eq=ql*wcq/1000\n",
-      "e3=pi*3/1000\n",
-      "e2=pi*24/1000\n",
-      "e=25*hl+12.5*ql+50*fl\n",
-      "efficiency=e/(e+e2+eh+eq+e3)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 88.4557217274 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.85, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "t1=7.0#hrs\n",
-      "t2=4.0#hrs\n",
-      "t3=8.0#hrs\n",
-      "t4=5.0#hrs\n",
-      "k1=3.0#kW\n",
-      "k2=8.0#kW\n",
-      "pf1=0.6\n",
-      "pf2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "x1=k1/(pf1*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=load/(1*load)\n",
-      "pc1=(0.5)**2*0.1\n",
-      "pc2=pc3=0.10\n",
-      "o1=k1*t1\n",
-      "o2=k2*t2\n",
-      "o3=k2*load\n",
-      "output=o1+o2+o3\n",
-      "wc1=pc1*t1\n",
-      "wc2=pc2*t2\n",
-      "wc3=pc3*t3\n",
-      "cu_loss=wc1+wc2+wc3\n",
-      "loss=400.0*24/10000\n",
-      "efficiency=output/(output+loss+cu_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficency= 98.27465179 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 142
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.86, Page Number:1185"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=.98\n",
-      "load=15.0#kVA\n",
-      "t1=12.0\n",
-      "t2=6.0\n",
-      "t3=6.0\n",
-      "pf1=0.8\n",
-      "pf2=0.8\n",
-      "pf3=0.9\n",
-      "k1=2.0\n",
-      "k2=12.0\n",
-      "k3=18.0\n",
-      "#calculations\n",
-      "output=load*1000\n",
-      "inpt=output/efficiency\n",
-      "loss=inpt-output\n",
-      "cu_loss=loss/2\n",
-      "x1=k1/(0.5*load)\n",
-      "x2=k2/(pf2*load)\n",
-      "x3=k3/(pf3*load)\n",
-      "wc1=0.131\n",
-      "wc2=0.918\n",
-      "wc3=1.632\n",
-      "o1=t1*k1\n",
-      "o2=t2*k2\n",
-      "o3=t3*k3\n",
-      "output=o1+o2+o3\n",
-      "loss=wc1+wc2+wc3+0.153*24\n",
-      "efficiency=(output*100)/(output+loss)\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 96.9798386522 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.87, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.0#kW\n",
-      "v1=115.0#V\n",
-      "v2=230.0#V\n",
-      "\n",
-      "#calculation\n",
-      "k=v1/v2\n",
-      "power=load*(1-k)\n",
-      "power2=k*load\n",
-      "\n",
-      "#result\n",
-      "print \"a)power transferred inductively=\",power,\"kW\"\n",
-      "print \"b)power transferred conductively=\",power2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)power transferred inductively= 1.5 kW\n",
-        "b)power transferred conductively= 1.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 145
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.88, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=500.0#V\n",
-      "v2=400.0#V\n",
-      "i=100.0#A\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "i1=k*i\n",
-      "saving=k*100\n",
-      "\n",
-      "#result\n",
-      "print \"economy of cu=\",saving"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "economy of cu= 80.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 147
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.89, Page Number:1188"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=500.0#KVA\n",
-      "f=50.0#Hz\n",
-      "v1=6600.0#V\n",
-      "v2=5000.0#V\n",
-      "e=8.0#V\n",
-      "phim1=1.3#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "phim=e/(4.44*f)\n",
-      "area=phim/phim1\n",
-      "n1=v1/e\n",
-      "n2=v2/e\n",
-      "\n",
-      "#result\n",
-      "print \"core area=\",area*10000,\"m2\"\n",
-      "print \"number of turns on the hv side=\",n1\n",
-      "print \"number of turns on the lv side=\",n2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "core area= 277.2002772 m2\n",
-        "number of turns on the hv side= 825.0\n",
-        "number of turns on the lv side= 625.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.90, Page Number:1189"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2640*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i1_-i2\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 219.12 kVA\n",
-        "iv)per cent increase in kVA= 1095.6 %\n",
-        "v)I1= 91.3 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.91, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#KVA\n",
-      "v1=2400.0#V\n",
-      "v2=240.0#V\n",
-      "\n",
-      "#calculation\n",
-      "i1=round(load*1000/v1,1)\n",
-      "k=v2/v1\n",
-      "i2=i1/k\n",
-      "kva=2160*i2*0.001\n",
-      "kva_per=kva*100/load\n",
-      "i1_=kva*1000/v1\n",
-      "ic=i2-i1_\n",
-      "over=ic*100/i1\n",
-      "\n",
-      "#result\n",
-      "print \"i)i1=\",i1,\"A\"\n",
-      "print \"ii)i2=\",i2,\"A\"\n",
-      "print \"iii)kVA rating=\",kva,\"kVA\"\n",
-      "print \"iv)per cent increase in kVA=\",kva_per,\"%\"\n",
-      "print \"v)I1=\",i1_,\"A\"\n",
-      "print \"  Ic=\",ic,\"A\"\n",
-      "print \"vi)per cent overload=\",over,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)i1= 8.3 A\n",
-        "ii)i2= 83.0 A\n",
-        "iii)kVA rating= 179.28 kVA\n",
-        "iv)per cent increase in kVA= 896.4 %\n",
-        "v)I1= 74.7 A\n",
-        "  Ic= 8.3 A\n",
-        "vi)per cent overload= 100.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 160
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.92, Page Number:1190"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5.0#kVA\n",
-      "v1=110.0#V\n",
-      "v2=110.0#V\n",
-      "f=50.0#Hz\n",
-      "efficiency=0.95\n",
-      "iron_loss=50.0#W\n",
-      "v=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=load*1000/efficiency-load*1000-iron_loss\n",
-      "efficiency=load*1000/(load*1000+cu_loss/4+iron_loss)\n",
-      "i2=(load*1000+cu_loss/4+iron_loss)/v\n",
-      "\n",
-      "#result\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"current drawn on hv side=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "efficiency= 97.9760216579 %\n",
-        "current drawn on hv side= 23.1967703349 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.93, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500#V\n",
-      "v2=2300#V\n",
-      "\n",
-      "#calculations\n",
-      "kva=(v1+v2)*50*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"voltage output=\",v1+v2,\"V\"\n",
-      "print \"kVA rating of auto transformer=\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage output= 13800 V\n",
-        "kVA rating of auto transformer= 690.0 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.94, Page Number:1191"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=11500.0#V\n",
-      "v2=2300.0#V\n",
-      "load=100.0#KVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*100/v1\n",
-      "i2=load*100/v2\n",
-      "kva1=(v1+v2)*i1/(100)\n",
-      "kva2=(v1+v2)*i2/(100)\n",
-      "#result\n",
-      "print \"voltage ratios=\",(v1+v2)/v1,\"or\",(v1+v2)/v2\n",
-      "print \"kVA rating in first case=\",kva1\n",
-      "print \"kVA rating in second case=\",kva2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage ratios= 1.2 or 6.0\n",
-        "kVA rating in first case= 120.0\n",
-        "kVA rating in second case= 600.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 167
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.95, Page Number:1192"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2400.0#v\n",
-      "v2=240.0#V\n",
-      "load=50.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "i1=load*1000/v1\n",
-      "i2=load*1000/v2\n",
-      "output=2640*i2\n",
-      "i=i2*2640/v1\n",
-      "k=2640/v1\n",
-      "poweri=v1*i1*0.001\n",
-      "power=output/1000-poweri\n",
-      "\n",
-      "#result\n",
-      "print \"rating of the auto-transformer=\",output/1000,\"kVA\"\n",
-      "print \"inductively transferred powers=\",poweri,\"kW\"\n",
-      "print \"conductively transferred powers=\",power,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rating of the auto-transformer= 550.0 kVA\n",
-        "inductively transferred powers= 50.0 kW\n",
-        "conductively transferred powers= 500.0 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 169
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.96, Page Number:1196"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "za=complex(0.5,3)\n",
-      "zb=complex(0.,10)\n",
-      "load=100#KW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa)*math.cos(math.atan(sa.imag/sa.real)),\"kW\"\n",
-      "print \"SB=\",abs(sb)*math.cos(math.atan(sb.imag/sb.real)),\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "96.082805253\n",
-        "SA= 74.5937961595 kW\n",
-        "SB= 25.4062038405 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 174
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.97, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r1=0.005#ohm\n",
-      "r2=0.01#ohm\n",
-      "x1=0.05#ohm\n",
-      "x2=0.04#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "za=complex(r1,x1)\n",
-      "zb=complex(r2,x2)\n",
-      "pf=math.cos(math.degrees((-1)*math.acos(pf))*math.degrees(math.atan((za/zb).imag/(za/zb).real)))\n",
-      "\n",
-      "#result\n",
-      "print \"load of B=\",abs(za/zb)\n",
-      "print \"pf of B=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load of B= 1.21872643265\n",
-        "pf of B= 0.613584256393\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.98, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=250#kVA\n",
-      "za=complex(1,6)\n",
-      "zb=complex(1.2,4.8)\n",
-      "load1=500#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "s=load1*complex(-pf,math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 224.451917244 -39.3923099293\n",
-        "SB= 275.942423833 -34.8183886694\n"
-       ]
-      }
-     ],
-     "prompt_number": 205
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.99, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabledeclaration\n",
-      "load=100.0#KW\n",
-      "r1=0.5\n",
-      "x1=8.0\n",
-      "r2=0.75\n",
-      "x2=4.0\n",
-      "load1=180.0#kW\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "load=load1/pf\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "z1=complex(r1,x1)\n",
-      "z2=complex(r2,x2)\n",
-      "s1=s*z2/(z1+z2)\n",
-      "s2=s*z1/(z1+z2)\n",
-      "kw1=abs(s1)*math.cos(math.atan(s1.imag/s1.real))\n",
-      "kw2=abs(s2)*math.cos(math.atan(s2.imag/s2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"kW1=\",kw1,\"kW\"\n",
-      "print \"kW2=\",kw2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "(1.25+12j)\n",
-        "kW1= 58.119626171 kW\n",
-        "kW2= 121.880373829 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.100, Page Number:1197"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=200.0#kW\n",
-      "pf=0.85\n",
-      "za=complex(1,5)\n",
-      "zb=complex(2,6)\n",
-      "\n",
-      "#calculations\n",
-      "s=load/pf*complex(0.85,-0.527)\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"kVA for A=\",abs(sa),math.cos(math.atan(sa.imag/sa.real)),\"lag\"\n",
-      "print \"kVA for B=\",abs(sb),math.cos(math.atan(sb.imag/sb.real)),\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA for A= 130.53263665 0.819364787986 lag\n",
-        "kVA for B= 105.238776124 0.884143252833 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.101, Page Number:1198"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=2200.0#V\n",
-      "v2=110.0#V\n",
-      "load=125.0#kVA\n",
-      "pf=0.8\n",
-      "za=complex(0.9,10)\n",
-      "zb=(100/50)*complex(1.0,5)\n",
-      "\n",
-      "#calculation\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 63.0780848499 -39.929442891 degrees\n",
-        "SB= 62.1031510961 -33.7622749748 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 218
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.102, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=500#kVA\n",
-      "za=complex(1,5)\n",
-      "load2=250#kVA\n",
-      "zb=complex(1.5,4)\n",
-      "v2=400#V\n",
-      "load=750#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zb=(500/load2)*zb\n",
-      "s=load*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 471.125736359 -40.3232138964 degrees\n",
-        "SB= 281.165527855 -31.0771011508 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 219
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.103, Page Number:1199"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=1000#A\n",
-      "pf=0.8\n",
-      "za=complex(2,3)\n",
-      "zb=complex(2.5,5)\n",
-      "\n",
-      "#calculations\n",
-      "i=i*complex(pf,-math.sin(math.acos(pf)))\n",
-      "ratio=zb/za\n",
-      "ib=i/(1+ratio)\n",
-      "ia=i-ib\n",
-      "ratio=ia.real/ib.real\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",ia\n",
-      "print \"IB=\",ib\n",
-      "print \"ratio of output=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= (504.451038576-341.246290801j)\n",
-        "IB= (295.548961424-258.753709199j)\n",
-        "ratio of output= 1.70682730924\n"
-       ]
-      }
-     ],
-     "prompt_number": 220
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.104, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v1=1000.0#V\n",
-      "v2=500.0#V\n",
-      "load=100.0#kVA\n",
-      "za=complex(1.0,5.0)\n",
-      "zb=complex(2.0,2.0)\n",
-      "load1=300.0#kVA\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "zb=(100.0/250)*zb\n",
-      "s=load1*complex(pf,-math.sin(math.acos(pf)))\n",
-      "sa=s*zb/(za+zb)\n",
-      "sb=s*za/(za+zb)\n",
-      "zab=za*zb/(za+zb)\n",
-      "drop=zab.real*240/100+zab.imag*180/100\n",
-      "v2=v2-v2*drop/100\n",
-      "\n",
-      "#result\n",
-      "print \"SA=\",abs(sa),math.degrees(math.atan(sa.imag/sa.real)),\"degrees\"\n",
-      "print \"SB=\",abs(sb),math.degrees(math.atan(sb.imag/sb.real)),\"degrees\"\n",
-      "print \"secondary voltage=\",v2,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "SA= 55.8895719399 -64.6284382469 degrees\n",
-        "SB= 251.890896741 -30.9383707209 degrees\n",
-        "secondary voltage= 486.177874187 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 223
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.105, Page Number:1200"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n11=5000.0\n",
-      "n12=440.0\n",
-      "load1=200#kVA\n",
-      "n21=5000.0\n",
-      "n22=480.0\n",
-      "load2=350#kVA\n",
-      "x=3.5\n",
-      "\n",
-      "#calculation\n",
-      "i1=load1*1000/n12\n",
-      "i2=load2*1000/n22\n",
-      "x1=x*n12/(100*i1)\n",
-      "x2=x*n22/(100*i2)\n",
-      "ic=(n22-n12)/0.057\n",
-      "\n",
-      "#result\n",
-      "print \"no-load circulation current=\",ic/i1,\"times the normal current of 200 kVA unit\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no-load circulation current= 1.54385964912 times the normal current of 200 kVA unit\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.106, Page Number:1203"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variabe declaration\n",
-      "ea=6600#V\n",
-      "eb=6400#V\n",
-      "za=complex(0.3,3)\n",
-      "zb=complex(0.2,1)\n",
-      "zl=complex(8.0,6.0)\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "\n",
-      "#result\n",
-      "print \"IA=\",abs(ia),\"A\"\n",
-      "print \"IB=\",abs(ib),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "IA= 195.492387533 A\n",
-        "IB= 422.567795916 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 227
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.107, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=100.0#kVA\n",
-      "load2=50.0#kVA\n",
-      "v1=1000.0#V\n",
-      "v2=950.0#V\n",
-      "r1=2.0\n",
-      "r2=2.5\n",
-      "x1=8.0\n",
-      "x2=6.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=load1*1000/v1\n",
-      "ra=v1*r1/(100*ia)\n",
-      "xa=v1*x1/(100*ia)\n",
-      "ib=load2*1000/v2\n",
-      "rb=v2*r2/(100*ib)\n",
-      "xb=v2*x2/(100*ib)\n",
-      "z=((ra+rb)**2+(xa+xb)**2)**0.5\n",
-      "ic=(v1-v2)/z\n",
-      "alpha=math.atan((xa+xb)/(ra+rb))\n",
-      "\n",
-      "#result\n",
-      "print \"no load circulating current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no load circulating current= 25.0948635944 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 32.108, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load1=1000.0#KVA\n",
-      "load2=500.0#kVA\n",
-      "v1=500.0#V\n",
-      "v2=510.0#V\n",
-      "z1=3.0\n",
-      "z2=5.0\n",
-      "r=0.4\n",
-      "\n",
-      "#calculation\n",
-      "ia=load1*1000/480\n",
-      "ib=load2*1000/480\n",
-      "za=z1*v1/(100*ia)\n",
-      "zb=z2*v2/(100*ib)\n",
-      "ic=(v2-v1)/(za+zb)\n",
-      "\n",
-      "#result\n",
-      "print \"cross current=\",ic,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "cross current= 315.656565657 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 233
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.109, Page Number:1204"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "loada=500.0#KVA\n",
-      "loadb=250.0#kVA\n",
-      "load=750.0#KVA\n",
-      "pf=0.8\n",
-      "v1=405.0#V\n",
-      "v2=415.0#V\n",
-      "ra=1.0\n",
-      "rb=1.5\n",
-      "xa=5.0\n",
-      "xb=4.0\n",
-      "\n",
-      "#calculations\n",
-      "ia=loada*1000/400\n",
-      "ra=400/(100*ia)\n",
-      "xa=xa*400/(100*ia)\n",
-      "ib=loadb*1000/400\n",
-      "rb=rb*400/(100*ib)\n",
-      "xb=xb*400/(100*ib)\n",
-      "za=complex(ra,xa)\n",
-      "zb=complex(rb,xb)\n",
-      "zl=400**2*0.001/load*complex(pf,math.sin(math.acos(pf)))\n",
-      "ic=(v1-v2)/(za+zb)\n",
-      "ia=(v1*zb+(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(v2*za-(v1-v2)*zl)/(za*zb+zl*(za+zb))\n",
-      "sa=400*ia/1000\n",
-      "sb=400*ib/1000\n",
-      "pf1=math.cos(math.atan(sa.imag/sa.real))\n",
-      "pf2=math.cos(math.atan(sb.imag/sb.real))\n",
-      "\n",
-      "#result\n",
-      "print \"a)cross current=\",-abs(ic),math.degrees(math.atan(ic.imag/ic.real))\n",
-      "print \"b)SA=\",abs(sa),pf1,\"lag\"\n",
-      "print \"  SB=\",abs(sb),pf2,\"lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)cross current= -229.754569404 -72.8972710309\n",
-        "b)SA= 387.844943528 0.820048560714 lag\n",
-        "  SB= 351.964386212 0.738709225528 lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.110, Page Number:1205"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zl=complex(2.0,1.5)\n",
-      "za=complex(0.15,0.5)\n",
-      "zb=complex(0.1,0.6)\n",
-      "ea=207#V\n",
-      "eb=205#V\n",
-      "\n",
-      "#calculations\n",
-      "ia=(ea*zb+(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "ib=(eb*za-(ea-eb)*zl)/(za*zb+zl*(za+zb))\n",
-      "v2_=(ia+ib)*zl\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ia.imag/ia.real)\n",
-      "pfa=math.cos(angle)\n",
-      "angle=math.atan(v2_.imag/v2_.real)-math.atan(ib.imag/ib.real)\n",
-      "pfb=math.cos(angle)\n",
-      "pa=abs(v2_)*abs(ia)*pfa\n",
-      "pb=abs(v2_)*abs(ib)*pfb\n",
-      "\n",
-      "#result\n",
-      "print \"power output:\"\n",
-      "print \" A:\",pa,\"W\"\n",
-      "print \" B:\",pb,\"W\"\n",
-      "print \"power factor:\"\n",
-      "print \" A:\",pfa\n",
-      "print \" B:\",pfb\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output:\n",
-        " A: 6535.37583042 W\n",
-        " B: 4925.36941503 W\n",
-        "power factor:\n",
-        " A: 0.818428780129\n",
-        " B: 0.775705655277\n"
-       ]
-      }
-     ],
-     "prompt_number": 248
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 32.111, Page Number:1206"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=200.0#A\n",
-      "ib=600.0#A\n",
-      "ra=0.02#ohm\n",
-      "rb=0.025#ohm\n",
-      "xa=0.05#ohm\n",
-      "xb=0.06#ohm\n",
-      "ea=245.0#V\n",
-      "eb=240.0#V\n",
-      "zl=complex(0.25,0.1)\n",
-      "\n",
-      "#calculation\n",
-      "za=(ea/ia)*complex(ra,xa)\n",
-      "zb=(eb/ib)*complex(rb,xb)\n",
-      "i=(ea*zb+eb*za)/(za*zb+zl*(za+zb))\n",
-      "v2=i*zl\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",round(abs(v2)),round(math.degrees(math.atan(v2.imag/v2.real))),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 230.0 -3.0 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_1.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_1.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_2.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_2.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_3.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_3.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_4.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_4.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_5.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_5.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_6.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_6.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_7.ipynb
deleted file mode 100755
index 495cee05..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter33_7.ipynb
+++ /dev/null
@@ -1,1433 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:62e227cc38186a0706017dd159987c82bd21be1d7e8602e20c55cf079ab30efe"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 33: Transformer:Three Phase"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.1, Page Number:1216"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=3\n",
-      "f=50.0#Hz\n",
-      "vd=22000.0#V\n",
-      "vs=400.0#V\n",
-      "phi=0.8\n",
-      "i=5.0#A\n",
-      "\n",
-      "#calcuations\n",
-      "v_phase_secondary=vs/math.sqrt(3)\n",
-      "K=(vs/vd)/math.sqrt(3)\n",
-      "i_primary=i/math.sqrt(3)\n",
-      "i_secondary=i_primary/K\n",
-      "il=i_secondary\n",
-      "output=math.sqrt(3)*il*vs*phi\n",
-      "\n",
-      "#result\n",
-      "print \"Output=\",output/10000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Output= 15.2420471066 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.2, Page Number:1217"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=500.0#kVA\n",
-      "f=50.0#Hz\n",
-      "vls=11.0#kV\n",
-      "vld=33.0#kV\n",
-      "rh=35.0#ohm\n",
-      "rl=0.876#ohm\n",
-      "iron_loss=3050.0#W\n",
-      "phi1=1.0\n",
-      "phi2=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "K=(vls*1000)/(math.sqrt(3)*vld*1000)\n",
-      "r02=rl+K**2*rh\n",
-      "i_Secondary=(w*1000)/(math.sqrt(3)*vls*1000)\n",
-      "#full load\n",
-      "fl_culoss=3*((w/(vls*math.sqrt(3)))**2)*r02\n",
-      "fl_totalloss=fl_culoss+iron_loss\n",
-      "fl_efficiency1=w*1000/(w*1000+fl_totalloss)\n",
-      "fl_efficiency2=(phi2*w*1000)/(w*phi2*1000+fl_totalloss)\n",
-      "#half load\n",
-      "cu_loss=.5**2*fl_culoss\n",
-      "totalloss=cu_loss+iron_loss\n",
-      "efficiency1=(w*1000/2)/((w*1000/2)+totalloss)\n",
-      "efficiency2=(w*1000*phi2/2)/((phi2*w*1000/2)+totalloss)\n",
-      "#result\n",
-      "print \"full load efficiency at p.f. 1=\",fl_efficiency1*100,\"%\"\n",
-      "print \"full load efficiency at p.f. 0.8=\",fl_efficiency2*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 1=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency at p.f. 0.8=\",round(efficiency2*100),\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency at p.f. 1= 98.5147491838 %\n",
-        "full load efficiency at p.f. 0.8= 98.1503046336 %\n",
-        "half load efficiency at p.f. 1= 98.3585709725 %\n",
-        "half load efficiency at p.f. 0.8= 98.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.3, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.02\n",
-      "va=2000\n",
-      "reactance=0.1\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculation\n",
-      "cu_loss=r*100*va/100\n",
-      "regn=r*100*math.cos(phi)+reactance*100*math.sin(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Cu loss=\",cu_loss,\"kW\"\n",
-      "print \"Regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Cu loss= 40.0 kW\n",
-        "Regulation= 7.6 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 39
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.4, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w=120.0#kVA\n",
-      "v1=6000.0\n",
-      "v2=400.0\n",
-      "f=50.0#Hz\n",
-      "iron_loss=1600.0#W\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss_fl=iron_loss*((4/3)**2)\n",
-      "fl_output=w*pf*1000\n",
-      "total_loss=iron_loss+cu_loss_fl\n",
-      "efficiency1=fl_output/(fl_output+total_loss)\n",
-      "cu_loss_hl=0.5**2*cu_loss_fl\n",
-      "total_loss2=cu_loss_hl+iron_loss\n",
-      "efficiency2=(w*1000/2)/((w*1000/2)+total_loss2)\n",
-      "total_loss3=2*iron_loss\n",
-      "output=(3.0/4)*w*1000\n",
-      "inpt=output+total_loss3\n",
-      "efficiency=output/inpt\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"full load efficiency=\",efficiency1*100,\"%\"\n",
-      "print \"half load efficiency=\",efficiency2*100,\"%\"\n",
-      "print \"3/4 load efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load efficiency= 96.7741935484 %\n",
-        "half load efficiency= 96.7741935484 %\n",
-        "3/4 load efficiency= 96.5665236052 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.5, Page Number:1218"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "rp=8.0#ohm\n",
-      "rs=0.08#ohm\n",
-      "z=0.07\n",
-      "pf=0.75\n",
-      "v1=33.0\n",
-      "v2=6.6\n",
-      "w=2*10.0**6\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "fl_i=w/(math.sqrt(3)*v2*10**3)\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rs+(rp*(K*K))\n",
-      "z_drop=z*v2*1000/math.sqrt(3)\n",
-      "z02=z_drop/fl_i\n",
-      "x02=math.sqrt((z02*z02)-(r02*r02))\n",
-      "drop=fl_i*(r02*math.cos(phi)+x02*math.sin(phi))\n",
-      "secondary_v=v2*1000/math.sqrt(3)\n",
-      "V2=secondary_v-drop\n",
-      "line_v=V2*math.sqrt(3)\n",
-      "regn=drop*100/secondary_v\n",
-      "\n",
-      "#result\n",
-      "print \"secondary voltage\",line_v,\"V\"\n",
-      "print \"regulation=\",regn,\"%\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary voltage 6254.29059005 V\n",
-        "regulation= 5.23802136291 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.6, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=100.0#kWA\n",
-      "f=50.0#Hz\n",
-      "v1=3300.0#V\n",
-      "v2=400.0#V\n",
-      "rh=3.5#ohm\n",
-      "rl=0.02#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.958\n",
-      "\n",
-      "#calculations\n",
-      "output=0.8*100\n",
-      "inpt=output/efficiency\n",
-      "total_loss=(inpt-output)*1000\n",
-      "K=v2/(math.sqrt(3)*v1)\n",
-      "r02=rl+K**2*rh\n",
-      "i2=((w*1000)/math.sqrt(3))/v2\n",
-      "cu_loss=3*i2**2*r02\n",
-      "iron_loss=total_loss-cu_loss\n",
-      "#result\n",
-      "print \"ironloss=\",iron_loss,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.0371411080502\n",
-        "2321.31925314\n",
-        "ironloss= 1185.98763622 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.7, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=5000.0#kVA\n",
-      "v1=6.6#kV\n",
-      "v2=33.0#kV\n",
-      "nl=15.0#kW\n",
-      "fl=50.0#kW\n",
-      "drop=0.07\n",
-      "load=3200.0#kw\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i2=w*1000/(math.sqrt(3)*v2*1000)\n",
-      "impedence_drop=drop*(v2/math.sqrt(3))*1000\n",
-      "z02=impedence_drop/i2\n",
-      "cu_loss=fl-nl\n",
-      "r02=cu_loss*1000/(3*i2**2)\n",
-      "x02=math.sqrt(z02**2-r02**2)\n",
-      "print \"full-load x02:\",x02\n",
-      "\n",
-      "#when load=3200#kW\n",
-      "i2=load/(math.sqrt(3)*v2*0.8)\n",
-      "drop_=drop*1000*(r02*math.cos(phi)+z02*math.sin(phi))\n",
-      "regn=(drop_*100)/(v2*1000/math.sqrt(3))\n",
-      "vp=v1+regn/100*v1\n",
-      "print \"Primary voltage=\",vp*1000,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load x02: 15.1695784661\n",
-        "Primary voltage= 6851.39317975 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 95
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.8, Page Number:1219"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=1\n",
-      "x=6\n",
-      "v=6600#V\n",
-      "v2=4800#V\n",
-      "pf=0.8\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "regn=(r*math.cos(phi)+z*math.sin(phi))\n",
-      "secondary_v=v2+regn/100*v2\n",
-      "secondary_vp=secondary_v/math.sqrt(3)\n",
-      "K=secondary_vp/v\n",
-      "\n",
-      "#result\n",
-      "print \"Transformation Ratio=\",K"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Transformation Ratio= 0.423426587968\n"
-       ]
-      }
-     ],
-     "prompt_number": 96
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.9, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "v1=6600#V\n",
-      "v2=400#V\n",
-      "pf=0.8\n",
-      "scv=400#V\n",
-      "sci=175#A\n",
-      "scw=17#kW\n",
-      "ocv=400#V\n",
-      "oci=150#A\n",
-      "ocw=15#kW\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "i1=sci/math.sqrt(3)\n",
-      "z01=scv/i1\n",
-      "r01=scw*1000/(3*i1*i1)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "r=i1*r01*100/v1\n",
-      "x=i1*x01*100/v1\n",
-      "regn=(r*math.cos(phi)-x*math.sin(phi))\n",
-      "I1=w*1000/(math.sqrt(3)*v1)\n",
-      "total_loss=scw+ocw\n",
-      "fl_output=w*pf\n",
-      "efficiency=fl_output/(fl_output+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"% resistance=\",r,\"%\"\n",
-      "print \"% reactance=\",x,\"%\"\n",
-      "print \"% efficiency=\",efficiency*100,\"%\"\n",
-      "print \"%regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "% resistance= 0.849779616989 %\n",
-        "% reactance= 6.00073499035 %\n",
-        "% efficiency= 98.0392156863 %\n",
-        "%regulation= -2.92061730062 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.10, Page Number:1220"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=11000.0#V\n",
-      "v2=440.0#V\n",
-      "i=5.0#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "secondary_rating=v2/math.sqrt(3)\n",
-      "primary_i=i/math.sqrt(3)\n",
-      "voltsamps=v1*5/math.sqrt(3)\n",
-      "i2=voltsamps/secondary_rating\n",
-      "output=pf*voltsamps/1000\n",
-      "\n",
-      "#result\n",
-      "print \"Each coil current=\",i2,\"A\"\n",
-      "print \"Total output=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Each coil current= 125.0 A\n",
-        "Total output= 25.4034118443 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.12, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kVA_per_transformer=load/2*1.15\n",
-      "delta_delta_rating=kVA_per_transformer*3\n",
-      "increase=(delta_delta_rating-load)*100/load\n",
-      "\n",
-      "#result\n",
-      "print \"increase=\",increase,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase= 72.5 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 126
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.13, Page Number:1224"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=20#kVA\n",
-      "v1=2300#v\n",
-      "v2=230#V\n",
-      "load=40#kVA\n",
-      "\n",
-      "#calculations\n",
-      "kva_load=load/math.sqrt(3)\n",
-      "percent_rated=kva_load*100/w\n",
-      "kvarating_vv=2*w*0.866\n",
-      "vv_delta=kvarating_vv*100/60\n",
-      "percentage_increase=kva_load/(load/3)\n",
-      "\n",
-      "#result\n",
-      "print \"i)kVA load of each transformer=\",kva_load,\"kVA\"\n",
-      "print \"ii)per cent of rated load carried by each transformer=\",percent_rated,\"%\"\n",
-      "print \"iii)total kVA rating of the V-V bank\",kvarating_vv,\"kVA\"\n",
-      "print \"iv)ratio of the v-v bank to delta-delta bank\",vv_delta,\"%\"\n",
-      "print \"v)percent increase in load=\",percentage_increase*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)kVA load of each transformer= 23.0940107676 kVA\n",
-        "ii)per cent of rated load carried by each transformer= 115.470053838 %\n",
-        "iii)total kVA rating of the V-V bank 34.64 kVA\n",
-        "iv)ratio of the v-v bank to delta-delta bank 57.7333333333 %\n",
-        "v)percent increase in load= 177.646236674 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 130
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.14, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=150.0#kW\n",
-      "v1=1000.0#V\n",
-      "pf=0.866\n",
-      "v=2000.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(pf*math.sqrt(3)*1000)\n",
-      "ip=il/math.sqrt(3)\n",
-      "ratio=v1/v\n",
-      "ip=ip*ratio\n",
-      "I=il\n",
-      "Ip=I*ratio\n",
-      "pf=86.6/100*pf\n",
-      "\n",
-      "#result\n",
-      "print \"delta-delta:current in the windings=\",ip,\"A\"\n",
-      "print \"v-v:current in the windings=\",Ip,\"A\"\n",
-      "print \"Power factor\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "delta-delta:current in the windings= 28.8683602771 A\n",
-        "v-v:current in the windings= 50.0014667312 A\n",
-        "Power factor 0.749956\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.15, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=3000#kW\n",
-      "v=11#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "I=load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "transformer_pf=86.6/100*pf\n",
-      "additional_load=72.5/100*load\n",
-      "total_load=additional_load+load\n",
-      "il=total_load*1000/(math.sqrt(3)*v*1000*pf)\n",
-      "\n",
-      "#result\n",
-      "print \"Il=\",il,\"A\"\n",
-      "print \"phase current=\",il/math.sqrt(3),\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Il= 339.521323075 A\n",
-        "phase current= 196.022727273 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.16, Page Number:1225"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=400#kVA\n",
-      "pf=0.866\n",
-      "v=440#V\n",
-      "\n",
-      "#calculations\n",
-      "kVA_each=(load/2)/pf\n",
-      "phi=math.acos(pf)\n",
-      "p1=kVA_each*math.cos(math.radians(30-phi))\n",
-      "p2=kVA_each*math.cos(math.radians(30+phi))\n",
-      "p=p1+p2\n",
-      "\n",
-      "#result\n",
-      "print \"kVA supplied by each transformer=\",kVA_each,\"kVA\"\n",
-      "print \"kW supplied by each transformer=\",p,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kVA supplied by each transformer= 230.946882217 kVA\n",
-        "kW supplied by each transformer= 399.995027715 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 136
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.17, Page Number:1228"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "load=33.0#kVA\n",
-      "v2=3300.0#V\n",
-      "\n",
-      "#calculations\n",
-      "vl=0.866*v2\n",
-      "ilp=load*1000/(math.sqrt(3)*v2)\n",
-      "ils=ilp/(440/v2)\n",
-      "main_kva=v2*ilp*0.001\n",
-      "teaser_kva=0.866*main_kva\n",
-      "\n",
-      "#result\n",
-      "print \"voltage rating of each coil=\",vl\n",
-      "print \"current rating of each coil=\",ils\n",
-      "print \"main kVA=\",main_kva,\"kVA\"\n",
-      "print \"teaser kVA=\",teaser_kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage rating of each coil= 2857.8\n",
-        "current rating of each coil= 43.3012701892\n",
-        "main kVA= 19.0525588833 kVA\n",
-        "teaser kVA= 16.4995159929 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 139
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.18, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "v2=200.0#V\n",
-      "output=150.0#kVA\n",
-      "\n",
-      "#calculations\n",
-      "ratio=v2/v\n",
-      "i2=output*1000/(2*v2)\n",
-      "i1=i2*ratio\n",
-      "primary_volts=(math.sqrt(3)*v)/2\n",
-      "ratio=v2/primary_volts\n",
-      "\n",
-      "#result\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"turns ratio\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "primary current= 170.454545455 A\n",
-        "turns ratio 0.524863881081\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.19, Page Number:1231"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=100.0#V\n",
-      "v2=3300.0#V\n",
-      "p=400.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2=p*1000/(pf*v)\n",
-      "ip=1.15*K*i2\n",
-      "I2m=K*i2\n",
-      "i2=ip/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#reslult\n",
-      "print \"Current=\",i1m,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 174.77684841 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.20, Page Number:1232"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "w1=300#kW\n",
-      "w2=450#kW\n",
-      "v1=100#V\n",
-      "pf=0.707\n",
-      "v2=3300#V\n",
-      "\n",
-      "#calculations\n",
-      "K=v/v2\n",
-      "i2t=(w2*1000)/(100*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "I2m=(K*w1*1000)/(100*pf)\n",
-      "i2=i1t/2\n",
-      "i1m=math.sqrt(I2m**2+i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"Current=\",i1m,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Current= 169.804606659 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.21, Page Number:1233"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=80.0#V\n",
-      "v2=11000.0#V\n",
-      "w1=500.0#kW\n",
-      "w2=800.0#kW\n",
-      "pf=0.5\n",
-      "\n",
-      "#calculations\n",
-      "K=v1/v2\n",
-      "#unity pf\n",
-      "i2t=w1*1000/v1\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/v1\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "\n",
-      "print \"unity pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n",
-      "#0.5 pf\n",
-      "i2t=w1*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=K*w2*1000/(v1*pf)\n",
-      "i1t_half=i1t/2\n",
-      "ip=math.sqrt(i2m**2+i1t_half**2)\n",
-      "print \"0.5 pf\"\n",
-      "print \"one 3 phase line carries\",i1t,\"A whereas the other 2 carry\",ip,\"A each\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "unity pf\n",
-        "one 3 phase line carries 52.2727272727 A whereas the other 2 carry 77.281082436 A each\n",
-        "0.5 pf\n",
-        "one 3 phase line carries 104.545454545 A whereas the other 2 carry 154.562164872 A each\n"
-       ]
-      }
-     ],
-     "prompt_number": 171
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.22, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=50#V\n",
-      "v2=4.6*1000#V\n",
-      "load=350#kW\n",
-      "w=200#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "K=v1/v2\n",
-      "i2t=w*1000/(v1*pf)\n",
-      "i1t=1.15*K*i2t\n",
-      "i2m=load*1000/(v1*pf)\n",
-      "Ki2m=K*i2m\n",
-      "i1t_half=i1t/2\n",
-      "i1m=math.sqrt(Ki2m**2+i1t_half**2)\n",
-      "\n",
-      "#result\n",
-      "print \"current in line A=\",i1t\n",
-      "print \"current in line B=\",i1m\n",
-      "print \"current in line C=\",i1m"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current in line A= 62.5\n",
-        "current in line B= 100.11107076\n",
-        "current in line C= 100.11107076\n"
-       ]
-      }
-     ],
-     "prompt_number": 173
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.23, Page Number:1234"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=231#V\n",
-      "v2=6600#v\n",
-      "volt_induced=8#v\n",
-      "\n",
-      "#calculations\n",
-      "hv=v2/volt_induced\n",
-      "vl=v*math.sqrt(3)\n",
-      "n_lv1=vl/volt_induced\n",
-      "n_lv2=math.sqrt(3)*n_lv1/2\n",
-      "n=2*n_lv2/3\n",
-      "\n",
-      "#result\n",
-      "print \"neutral point is located on the\",math.ceil(n),\"th turn from A downwards\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "neutral point is located on the 29.0 th turn from A downwards\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.24, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6000.0#V\n",
-      "v2=440.0#V\n",
-      "f=50.0#Hz\n",
-      "area=300.0#cm2\n",
-      "flux=1.2#Wb/m2\n",
-      "\n",
-      "#calculations\n",
-      "n1=v/(4.44*f*flux*area*0.0001*0.9)\n",
-      "K=v2/v\n",
-      "n2=n1*K\n",
-      "n_lv=math.sqrt(3)*n2/2\n",
-      "turns=n_lv*2/3\n",
-      "\n",
-      "#result\n",
-      "print \"NUmber of turns in AN=\",math.floor(turns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " NUmber of turns in AN= 35.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 183
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.25, Page Number:1235"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=250.0#V\n",
-      "load=30.0#kVA\n",
-      "v2=250.0#V\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(math.sqrt(3)*v2)\n",
-      "vl=0.866*v2\n",
-      "kva=il*vl*(0.001)\n",
-      "\n",
-      "#result\n",
-      "print \"Voltage=\",vl,\"V\"\n",
-      "print \"kVA rating\",kva,\"kVA\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Voltage= 216.5 V\n",
-        "kVA rating 14.9995599935 kVA\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.26, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#vaiable declaration\n",
-      "load=500#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,6)\n",
-      "zb=complex(2,5)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "s=load*complex(math.cos(phi),math.sin(phi))\n",
-      "z1=za/zb\n",
-      "z2=zb/za\n",
-      "sa=s/(1+z1)\n",
-      "sb=s/(1+z2)\n",
-      "pfa=cmath.phase(sa)\n",
-      "pfb=cmath.phase(sb)\n",
-      "#result\n",
-      "print \"sa=\",abs(sa)\n",
-      "print \"sb=\",abs(sb)\n",
-      "print \"cos phi_a=\",pfa\n",
-      "print \"cos phi_b=\",pfb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 230.042839552\n",
-        "sb= 270.171613479\n",
-        "cos phi_a= 0.611765735265\n",
-        "cos phi_b= 0.670521557981\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.27, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "w=2000#kVA\n",
-      "w1=4000#kVA\n",
-      "w2=5000#kVA\n",
-      "pf=0.8\n",
-      "za=complex(2,8)\n",
-      "zb=complex(1.6,3)\n",
-      "\n",
-      "#calculations\n",
-      "za_per=(w1/w)*za\n",
-      "zb_per=zb\n",
-      "z=za_per+zb_per\n",
-      "s=complex(w1,w-w2)\n",
-      "sb=s*(za/z)\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (2284.2287695-1821.49046794j)\n",
-        "sb= (1715.7712305-1178.50953206j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 211
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.28, Page Number:1237"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=1400#kVA\n",
-      "pf=0.866\n",
-      "w1=1000#kVA\n",
-      "w2=500#kVA\n",
-      "v1=6600\n",
-      "v2=400\n",
-      "za=complex(0.001,0.003)\n",
-      "zb=complex(0.0028,0.005)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (929.911014012-588.664867724j)\n",
-        "sb= (282.488985988-111.396729565j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.29, Page Number:1238"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "load=750#kVA\n",
-      "pf=0.707\n",
-      "w1=500#kVA\n",
-      "w2=250#kVA\n",
-      "v1=3300\n",
-      "v2=400\n",
-      "za=complex(2,3)\n",
-      "zb=complex(1.5,4)\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "zb=(w1/w2)*zb\n",
-      "z=za/(za+zb)\n",
-      "x=math.cos(-phi)\n",
-      "y=math.sin(-phi)*1j\n",
-      "s=load*(x+y)\n",
-      "sb=s*z\n",
-      "sa=s-sb\n",
-      "per_r=za.real*(sa.real)/w1\n",
-      "per_x=(za.imag)*(sa.imag)/w1\n",
-      "total_per=per_r+per_x\n",
-      "vl=v2-(total_per*4)\n",
-      "#result\n",
-      "print \"sa=\",sa\n",
-      "print \"sb=\",sb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= (399.511103547-348.770523615j)\n",
-        "sb= (130.738896453-181.639636072j)\n"
-       ]
-      }
-     ],
-     "prompt_number": 242
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.30, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratio=100/5\n",
-      "i=5#A\n",
-      "i1=3.5#A\n",
-      "\n",
-      "#calculations\n",
-      "il=i1*ratio\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 70.0 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 214
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 33.31, Page Number:1240"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i1=2000#A\n",
-      "i2=2500#A\n",
-      "i=5#A\n",
-      "\n",
-      "#calculations\n",
-      "ratio1=i1/i\n",
-      "ratio2=i2/i\n",
-      "\n",
-      "#result\n",
-      "print \"ratio in first case=\",ratio1\n",
-      "print \"ratio in second case=\",ratio2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio in first case= 400\n",
-        "ratio in second case= 500\n"
-       ]
-      }
-     ],
-     "prompt_number": 216
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_1.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_1.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_2.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_2.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_3.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_3.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_4.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_4.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_5.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_5.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_6.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_6.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_7.ipynb
deleted file mode 100755
index d05f1eeb..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter34_7.ipynb
+++ /dev/null
@@ -1,3065 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:0f43ef5b4c05930620c5e3871d199970ead64e15a20629e8e926abd11e2e9167"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 34:Induction Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.1, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=290.0#rpm\n",
-      "f=50.0#Hz\n",
-      "Ns=300.0#rpm(considered)\n",
-      "#calculation\n",
-      "P=120*f/Ns\n",
-      "s=(Ns-n)/Ns\n",
-      "\n",
-      "#result\n",
-      "print \"no. of poles=\",P\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "no. of poles= 20.0\n",
-        "slip= 3.33333333333 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.2, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "slot=3\n",
-      "f=50#Hz\n",
-      "\n",
-      "#calculation\n",
-      "P=2*n\n",
-      "slots_total=slot*P*n\n",
-      "Ns=120*f/P\n",
-      "\n",
-      "#result\n",
-      "print \"No. of stator poles=\",P\n",
-      "print \"Total number of slots=\",slots_total\n",
-      "print \"Speed=\",Ns,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " No. of stator poles= 6\n",
-        "Total number of slots= 54\n",
-        "Speed= 1000 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 5
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.3, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "slip1=0.04\n",
-      "slip2=0.03\n",
-      "\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip1)\n",
-      "f1=slip2*f*60\n",
-      "#at standstill s=1\n",
-      "f2=1*f\n",
-      "\n",
-      "#calculation\n",
-      "print \"speed at which magnetic field of the stator is rotating=\",Ns,\"rpm\"\n",
-      "print \"speed of the rotor when the slip is 0.04=\",N\n",
-      "print \"frequency of rotor current=\",f1,\"rpm\"\n",
-      "print \"frequency of the rotor current at standstill=\",f2,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at which magnetic field of the stator is rotating= 1500 rpm\n",
-        "speed of the rotor when the slip is 0.04= 1440.0\n",
-        "frequency of rotor current= 90.0 rpm\n",
-        "frequency of the rotor current at standstill= 50 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 7
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.4, Page Number:1255"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3.0\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slip=0.04\n",
-      "n=600.0#rpm\n",
-      "\n",
-      "#calculations\n",
-      "Ns=120*f/p\n",
-      "N=Ns*(1-slip)\n",
-      "s=(Ns-n)/Ns\n",
-      "f1=s*f\n",
-      "\n",
-      "#result\n",
-      "print \"the synchronous speed=\",Ns,\"rpm\"\n",
-      "print \"the rotor speed=\",N,\"rpm\"\n",
-      "print \"the rotor frequency when n=600 rpm=\",f1,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the synchronous speed= 1500.0 rpm\n",
-        "the rotor speed= 1440.0 rpm\n",
-        "the rotor frequency when n=600 rpm= 30.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.5, Page Number:1256"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "n=3\n",
-      "N=500#rpm\n",
-      "p2=8\n",
-      "slip=0.03\n",
-      "\n",
-      "#calculation\n",
-      "f=p*N/120\n",
-      "Ns=120*f/p2\n",
-      "N=Ns-slip*Ns\n",
-      "\n",
-      "#result\n",
-      "print \"full load speed of the motor=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full load speed of the motor= 727.5 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.6, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e=80#V\n",
-      "r=1#ohm\n",
-      "x=4#ohm\n",
-      "rheo=3#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E=e/(3)**0.5\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=E/z\n",
-      "pf=r/z\n",
-      "R=rheo+r\n",
-      "z2=(R**2+x**2)**0.5\n",
-      "i2=E/z2\n",
-      "\n",
-      "pf2=R/z2\n",
-      "\n",
-      "#result\n",
-      "print \"slip rings are short circuited:\"\n",
-      "print \"current/phase\",i,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"slip rings are onnected to a star-connected rheostat of 3  ohm\",\n",
-      "print \"current/phase\",i2,\"A\"\n",
-      "print \"pf=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip rings are short circuited:\n",
-        "current/phase 11.2022406722 A\n",
-        "pf= 0.242535625036\n",
-        "slip rings are onnected to a star-connected rheostat of 3  ohm current/phase 8.16496580928 A\n",
-        "pf= 0.707106781187\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.7, Page Number:1258"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "v=400#V\n",
-      "ratio=6.5\n",
-      "r=0.05#ohm\n",
-      "x=0.25#ohm\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=v*k/(3**0.5)\n",
-      "R=x-r\n",
-      "r2=x\n",
-      "z=(x**2+r2**2)**0.5\n",
-      "i2=e2/z\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",R,\"ohm\"\n",
-      "print \"starting current=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.2 ohm\n",
-        "starting current= 100.491886883 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.8, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=1100#V\n",
-      "f=50#Hz\n",
-      "ratio=3.8\n",
-      "r=0.012#ohm\n",
-      "x=0.25#ohm\n",
-      "s=0.04\n",
-      "#calculation\n",
-      "e=v/ratio\n",
-      "z=(r**2+x**2)**0.5\n",
-      "i=e/z\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "er=s*e\n",
-      "i2=er/zr\n",
-      "pf2=r/zr\n",
-      "i2=100*ratio\n",
-      "z2=e/i2\n",
-      "r2=(z2**2-x**2)**0.5\n",
-      "R=r2-r\n",
-      "\n",
-      "#result\n",
-      "print \"current with slip rings shorted=\",i,\"A\"\n",
-      "print \"pf with slip rings shorted=\",pf\n",
-      "print \"current with slip=4% and slip rings shorted=\",i2\n",
-      "print \"pf withslip=4% and slip rings shorted=\",pf2\n",
-      "print \"external resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current with slip rings shorted= 1156.56314266 A\n",
-        "pf with slip rings shorted= 0.0479447993684\n",
-        "current with slip=4% and slip rings shorted= 380.0\n",
-        "pf withslip=4% and slip rings shorted= 0.768221279597\n",
-        "external resistance= 0.70758173952 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.9, Page Number:1259"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=15#kW\n",
-      "v=3000#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "ratio=3.6\n",
-      "r=0.13#ohm\n",
-      "l=3.61*0.001#H\n",
-      "\n",
-      "#calculation\n",
-      "v=v/3**0.5\n",
-      "x2=2*3.14*l*f\n",
-      "k=1/ratio\n",
-      "r2_=0.1/k**2\n",
-      "x2_=ratio**2*x2\n",
-      "is1=v/((r**2+x2_**2)**0.5)\n",
-      "ns=120*f/p\n",
-      "ts=(3*3/(2*3.14*f))*((v**2)*r2_)/(r2_**2+x2_**2)\n",
-      "\n",
-      "#result\n",
-      "print \"starting current=\",is1,\"A\"\n",
-      "print \"ts=\",ts,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 117.896733436 A\n",
-        "ts= 512.375725888 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.10, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "zs=complex(0.4,4)\n",
-      "zr=complex(6,2)\n",
-      "v=80#V\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/3**0.5\n",
-      "i=e2/abs(zr+zs)\n",
-      "er=s*e2\n",
-      "xr=s*zs.imag\n",
-      "ir=er/abs(complex(zs.real,xr))\n",
-      "\n",
-      "#result\n",
-      "print \"rotor current at standstill=\",i,\"A\"\n",
-      "print \"rotor current when slip-rings are short-circuited=\",ir,\"A\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor current at standstill= 5.26498126493 A\n",
-        "rotor current when slip-rings are short-circuited= 3.31800758166 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.11, Page Number:1261"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "e=120#V\n",
-      "r2=0.3#ohm\n",
-      "x2=1.5#ohm\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "e2=e/3**0.5\n",
-      "er=s*e2\n",
-      "xr=s*x2\n",
-      "zr=(r2**2+xr**2)**0.5\n",
-      "i=er/zr\n",
-      "s=r2/x2\n",
-      "xr=s*x2\n",
-      "zr=(xr**2+r2**2)**0.5\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "\n",
-      "#result\n",
-      "print \"rotor when running short-circuited=\",i,\"A\"\n",
-      "print \"slip=\",s\n",
-      "print \"current when torque is maximum=\",i2,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor when running short-circuited= 9.05821627316 A\n",
-        "slip= 0.2\n",
-        "current when torque is maximum= 32.6598632371 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.12, Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tb=150.0#kg-m\n",
-      "n=660.0#rpm\n",
-      "r=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "t=tb*(2/((sb/s)+s/sb))\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",t,\"kg-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 90.0 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(a), Page Number:1266"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variablde declaration\n",
-      "n=3\n",
-      "vd=0.90\n",
-      "\n",
-      "#calculation\n",
-      "ratio_s=(1/vd)**2\n",
-      "ratio_i=ratio_s*vd\n",
-      "cu_loss_increase=ratio_i**2\n",
-      "\n",
-      "#result\n",
-      "print \"increase in motor copper losses=\",cu_loss_increase"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in motor copper losses= 1.23456790123\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.13(b), Page Number:1264"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "p1=15.0#kW\n",
-      "n=980.0#rpm\n",
-      "efficiency=0.93\n",
-      "vd=0.10\n",
-      "fd=0.05\n",
-      "\n",
-      "#calculation\n",
-      "v2=(1-vd)*v\n",
-      "f2=(1-fd)*f\n",
-      "n1=120*f/p\n",
-      "n2=120*f2/p\n",
-      "s1=(n1-n)/n1\n",
-      "ratio_f=s1*(v*(1-vd)/v)**2*f2/f\n",
-      "n2=n2*(1-ratio_f)\n",
-      "p2=p1*n2/n1\n",
-      "#result\n",
-      "print \"the new operating speed=\",n2,\"rpm\"\n",
-      "print \"the new output power=\",p2,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "the new operating speed= 935.3795 rpm\n",
-        "the new output power= 14.0306925 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(a), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=3\n",
-      "v1=400#V\n",
-      "v2=200#V\n",
-      "r=0.06#ohm\n",
-      "x=0.3#ohm\n",
-      "a=1\n",
-      "#calculations\n",
-      "r=x-r\n",
-      "\n",
-      "#result\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "additional resistance= 0.24 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(b), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "n=3\n",
-      "f=50#Hz\n",
-      "p=8\n",
-      "s=0.02\n",
-      "r=0.001#ohm\n",
-      "x=0.005#ohm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "a=r/x\n",
-      "n2=(1-s)*ns\n",
-      "ratio=2*s**2*a/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of the maximum to full-load torque=\",ratio*1000,\"10^-3\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of the maximum to full-load torque= 3.9603960396 10^-3\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.14(c), Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=12\n",
-      "v=600#V\n",
-      "f=50#Hz\n",
-      "r=0.03#ohm\n",
-      "x=0.5#ohm\n",
-      "n=495#rpm\n",
-      "s=0.01\n",
-      "#calculation\n",
-      "Ns=120*f/p\n",
-      "a=r/x\n",
-      "n=Ns*(1-a)\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed of max torque=\",n,\"rpm\"\n",
-      "print \"ratio of torques=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of max torque= 470.0 rpm\n",
-        "ratio of torques= 0.324324324324\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.15, Page Number:1267"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=746.0#kW\n",
-      "f=50.0#Hz\n",
-      "p=16\n",
-      "zr=complex(0.02,0.15)\n",
-      "n=360.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "a=zr.real/zr.imag\n",
-      "ratio=2*a*s/(a**2+s**2)\n",
-      "N=ns*(1-a)\n",
-      "R=zr.imag-zr.real\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",ratio\n",
-      "print \"speed at maximum torque=\",N,\"rpm\"\n",
-      "print \"rotor resistance=\",R,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 0.550458715596\n",
-        "speed at maximum torque= 325.0 rpm\n",
-        "rotor resistance= 0.13 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.16, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "r=0.025#ohm\n",
-      "x=0.12#ohm\n",
-      "ratio=3.0/4.0\n",
-      "\n",
-      "#calculations\n",
-      "s=r/x\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "a=solve(ratio-(2*a/(1+a**2)),a)\n",
-      "r=a[0]*x-r\n",
-      "\n",
-      "#result\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"additional resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed at maximum torque= 1187.5 rpm\n",
-        "additional resistance= 0.0291699475574164 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.17, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "p=8\n",
-      "#calculation\n",
-      "a=r/x\n",
-      "t_ratio=2*a*s/(a**2+s**2)\n",
-      "ns=120*f/p\n",
-      "n=(1-a)*ns\n",
-      "\n",
-      "#result\n",
-      "print \"ratio of torques=\",1/t_ratio\n",
-      "print \"speed=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio of torques= 1.45\n",
-        "speed= 675.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 26
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.18, Page Number:1268"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "a=Symbol('a')\n",
-      "a2=Symbol('a2')\n",
-      "p=3\n",
-      "t_ratio=2.5\n",
-      "t_ratio2=1.5\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "t_ratio3=t_ratio2/t_ratio\n",
-      "a=solve(t_ratio3-(2*a/(1+a**2)),a)\n",
-      "a2=solve(a2**2-0.15*a2+0.0009,a2)\n",
-      "r_red=(a[0]-a2[1])/a[0]\n",
-      "#result\n",
-      "print \"percentage reduction in rotor circuit resistance=\",r_red*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction in rotor circuit resistance= 56.8784093726987 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 46
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.19, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50#Hz\n",
-      "r=0.08#ohm\n",
-      "n=650.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "a=1\n",
-      "r=a*x2-r\n",
-      "#result\n",
-      "print \"extra resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "extra resistance= 0.52 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 51
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.20, Page Number:1269"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "R=Symbol('R')\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "t=162.8#N-m\n",
-      "n=1365.0#rpm\n",
-      "r=0.2#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "sb=(ns-n)/ns\n",
-      "x2=r/sb\n",
-      "R=solve(1.0/(4*x2)-((r+R)/((r+R)**2+x2**2)),R)\n",
-      "\n",
-      "#result\n",
-      "print \"resistance to be added=\",round(R[0],1),\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance to be added= 0.4 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.21, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "load=7.46#kW\n",
-      "t_ratios=1.60\n",
-      "t_ratiom=2.0\n",
-      "\n",
-      "#calcualtion\n",
-      "t_ratio=t_ratios/t_ratiom\n",
-      "#0.8a2-2*a+0.8 a=0.04\n",
-      "#0.5=2*a*sf/a2+sf2 sf=0.01\n",
-      "a=0.04\n",
-      "sf=0.01\n",
-      "ns=120*f/p\n",
-      "n=ns-sf*ns\n",
-      "N=ns-a*ns\n",
-      "\n",
-      "#result\n",
-      "print \"full-load speed=\",n,\"rpm\"\n",
-      "print \"speed at maximum torque=\",N,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "full-load speed= 1485.0 rpm\n",
-        "speed at maximum torque= 1440.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.22, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "v=240#V\n",
-      "f=50#Hz\n",
-      "r=0.12#ohm\n",
-      "x=0.85#ohm\n",
-      "ratio=1.8\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e2=k*(v/3**0.5)\n",
-      "ns=120*f/p\n",
-      "tf=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "s=r/x\n",
-      "tmax=(3/(2*3.14*f/3))*(s*e2*e2*r/(r**2+(s*x)**2))\n",
-      "n=ns*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"developed torque=\",tf,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "developed torque= 52.4097855621 N-m\n",
-        "maximum torque= 99.9125764956 N-m\n",
-        "speed at maximum torque= 858.823529412 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 16
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.23, Page Number:1270"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "ns=100#rpm considered\n",
-      "n=(1-s)*ns\n",
-      "n2=n/2\n",
-      "s2=(ns-n2)/ns\n",
-      "ratio=((s2/s)*(r**2+(s*x)**2)/(r**2+(s2*x)**2))**0.5\n",
-      "per=1-1/ratio\n",
-      "phi=math.atan(s2*x/r)\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"percentage reduction=\",per*100,\"%\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage reduction= 22.8528060715 %\n",
-        "pf= 0.307902262948\n"
-       ]
-      }
-     ],
-     "prompt_number": 17
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.26, Page Number:1272"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "t=100#N-m\n",
-      "n=1200#rpm\n",
-      "\n",
-      "#calculation\n",
-      "e2=v/2\n",
-      "ns=120*f/p\n",
-      "n=ns-n\n",
-      "n2=n+ns/2\n",
-      "\n",
-      "#result\n",
-      "print \"stator supply voltage=\",e2,\"V\"\n",
-      "print \"new speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator supply voltage= 220 V\n",
-        "new speed= 1050 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.24, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable delclaration\n",
-      "v=400.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=1140.0#rpm\n",
-      "e=440.0#V\n",
-      "e2=550.0#V\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "s1=(ns-n)/ns\n",
-      "s2=s1*(e/e2)**2\n",
-      "n2=ns*(1-s2)\n",
-      "\n",
-      "#result\n",
-      "print \"speed=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed= 1053.6 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 21
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.25, Page Number:1274"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=450.0#V\n",
-      "f=60.0#Hz\n",
-      "p=8.0\n",
-      "n=873.0#rpm\n",
-      "t=23.0#degrees\n",
-      "n2=864.0#rpm\n",
-      "alpha=1.0/234.0#per degrees centrigrade\n",
-      "\n",
-      "#calculation\n",
-      "s1=(900-n)/900\n",
-      "s2=(900-n2)/900\n",
-      "ratio=s2/s1-1\n",
-      "t2=(s2/s1-1)/alpha+23  \n",
-      "\n",
-      "#result\n",
-      "print \"increase in rotor resistance=\",ratio*100,\"%\"\n",
-      "print \"approx temperature=\",t2,\"degrees centigrade\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "increase in rotor resistance= 33.3333333333 %\n",
-        "approx temperature= 101.0 degrees centigrade\n"
-       ]
-      }
-     ],
-     "prompt_number": 24
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.27, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=500.0#Hz\n",
-      "p=6.0\n",
-      "load=80.0#kW\n",
-      "alt=100.0\n",
-      "ns=120.0*f/60.0\n",
-      "#calculation\n",
-      "s=alt/(60.0*f)\n",
-      "n=(1-s)*ns\n",
-      "cu_loss=(1.0/3.0)*load*1000/3.0\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*1000,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss=\",cu_loss/10000,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 996.666666667 rpm\n",
-        "rotor copper loss= 0.888888888889 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.28, Page Number:1283"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4.0\n",
-      "n=1425.0#rpm\n",
-      "z=complex(0.4,4)\n",
-      "ratio=0.8\n",
-      "loss=500.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=75/ns\n",
-      "e1=v/3**0.5\n",
-      "tf=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "ir=s*ratio*e1/(z.real**2+(s*z.imag)**2)**0.5\n",
-      "cu_loss=3*ir**2*z.real\n",
-      "pm=2*3.4*(n/60)*tf\n",
-      "pout=pm-loss\n",
-      "s=z.real/z.imag\n",
-      "tmax=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real*s)/(z.real**2+(s*z.imag)**2)\n",
-      "nmax=ns-s*ns\n",
-      "i=ratio*e1/abs(z)\n",
-      "tst=(3*2/(2*3.14*f))*(((e1*ratio)**2)*z.real)/(z.real**2+(z.imag)**2)\n",
-      "\n",
-      "#result\n",
-      "print \" full load torque=\",tf,\"N-m\"\n",
-      "print \"rotor current=\",ir,\"A\"\n",
-      "print \"cu_loss=\",cu_loss,\"W\"\n",
-      "print \"power output=\",pout,\"W\"\n",
-      "print \"max torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",nmax,\"rpm\"\n",
-      "print \"starting current=\",i,\"A\"\n",
-      "print \"starting torque=\",tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " full load torque= 78.9197452229 N-m\n",
-        "rotor current= 22.7215022978 A\n",
-        "cu_loss= 619.52 W\n",
-        "power output= 12245.5388535 W\n",
-        "max torque= 98.6496815287 N-m\n",
-        "speed at max torque= 1350.0 rpm\n",
-        "starting current= 50.5546790867 A\n",
-        "starting torque= 19.5345904017 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.30, Page Number:1286"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60#kW\n",
-      "loss=1#kW\n",
-      "s=0.03\n",
-      "\n",
-      "#calculations\n",
-      "p2=load-loss\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2\n",
-      "rotor_loss=cu_loss*1000/3\n",
-      "\n",
-      "#result\n",
-      "print \"mechanical power developed=\",pm,\"kW\"\n",
-      "print \"rotor copper loss=\",rotor_loss,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power developed= 57.23 kW\n",
-        "rotor copper loss= 590.0 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 52
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.31, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=20#KW\n",
-      "s=0.03\n",
-      "i=60#A\n",
-      "\n",
-      "#calculation\n",
-      "fr=s*f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss=s*load*1000\n",
-      "r2=cu_loss/(3*i**2)\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of rotor current=\",fr,\"Hz\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"W\"\n",
-      "print \"rotor resistance=\",r2,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of rotor current= 1.5 Hz\n",
-        "rotor copper loss= 600.0 W\n",
-        "rotor resistance= 0.0555555555556 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 54
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.32, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50#Hz\n",
-      "load=3.73#KW\n",
-      "n=960#rpm\n",
-      "loss=280#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "input_r=load*1000*ns/n\n",
-      "input_s=input_r+loss\n",
-      "\n",
-      "#result\n",
-      "print \"stator input=\",input_s,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator input= 4165.41666667 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.33, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=75.0#KW\n",
-      "alt=100.0\n",
-      "\n",
-      "#calculations\n",
-      "f1=alt/60\n",
-      "s=f1/f\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "cu_loss_r_per_phase=s*p2/3\n",
-      "pm=(1-s)*p2\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"rotor copper loss per phase=\",cu_loss_r_per_phase,\"kW\"\n",
-      "print \"mechancal power=\",pm,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.33333333333 %\n",
-        "rotor speed= 966.666666667 rpm\n",
-        "rotor copper loss per phase= 0.833333333333 kW\n",
-        "mechancal power= 72.5 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 57
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.34, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=500.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "n=975.0#rpm\n",
-      "p1=40.0#KW\n",
-      "loss_s=1.0#kW\n",
-      "loss=2.0#KW\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "p2=p1-loss_s\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "pout=pm-loss\n",
-      "efficiency=pout/p1\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor copper loss=\",cu_loss,\"kW\"\n",
-      "print \"shaft power=\",pout,\"kW\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 2.5 %\n",
-        "rotor copper loss= 0.975 kW\n",
-        "shaft power= 36.025 kW\n",
-        "efficiency= 90.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 59
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.35, Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "output=100#KW\n",
-      "v=3300#V\n",
-      "f=50#Hz\n",
-      "n=500#rpm\n",
-      "s=0.018\n",
-      "pf=0.85\n",
-      "cu_loss=2440#W\n",
-      "iron_loss=3500#W\n",
-      "rotational_loss=1200#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output+rotational_loss/1000\n",
-      "cu_loss_r=(s/(1-s))*pm\n",
-      "p2=pm+cu_loss_r\n",
-      "input_s=p2+cu_loss/1000+iron_loss/1000\n",
-      "il=input_s*1000/(3**0.5*v*pf)\n",
-      "efficiency=output/input_s\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss_r,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.85132382892 kW\n",
-        "line current= 22.1989272175 A\n",
-        "efficiency= 92.7202341611 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.36, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "f=50.0#Hz\n",
-      "p=6.0\n",
-      "p2=100.0#W\n",
-      "c=120.0\n",
-      "\n",
-      "#calculations\n",
-      "s=c/(f*60)\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pm=(1-s)*p2\n",
-      "cu_loss=s*p2/3\n",
-      "n2=ns-n\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"copper loss=\",cu_loss,\"kW\"\n",
-      "print \"speed of stator field with respect to rotor=\",n2,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 960.0 rpm\n",
-        "mechanical power= 96.0 kW\n",
-        "copper loss= 1.33333333333 kW\n",
-        "speed of stator field with respect to rotor= 40.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.37, Page Number:1288"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "efficiency=0.9\n",
-      "output=37#kW\n",
-      "ratio=1.0/3.0\n",
-      "\n",
-      "#calculation\n",
-      "input_m=output*1000/efficiency\n",
-      "total_loss=input_m-output*1000\n",
-      "x=total_loss/(3+0.5)\n",
-      "input_r=output*1000+x/2+x\n",
-      "s=x/input_r\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 3.0303030303 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 74
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.38, Page Number:1289"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=6\n",
-      "load=45#KW\n",
-      "i=75#A\n",
-      "s=0.03\n",
-      "iron_loss=1200#kW\n",
-      "loss=900#kW\n",
-      "r=0.12#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=load*1000/(3**0.5*v*i)\n",
-      "r=r*3/2\n",
-      "cu_loss=3*(i/3**0.5)**2*r\n",
-      "cu_loss_r=s*42788\n",
-      "pm=42788-cu_loss_r\n",
-      "output_s=pm-loss\n",
-      "efficiency=output_s/(load*1000)\n",
-      "t=(output_s*60)/(2*3.14*970)\n",
-      "\n",
-      "#result\n",
-      "print \"pf=\",pf\n",
-      "print \"rotor cu loss=\",cu_loss_r,\"W\"\n",
-      "print \"p out=\",output_s,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n",
-      "print \"torque=\",t,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf= 0.866025403784\n",
-        "rotor cu loss= 1283.64 W\n",
-        "p out= 40604.36 W\n",
-        "efficiency= 90.2319111111 %\n",
-        "torque= 399.937881673 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(a), Page Number:1287"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=1.75\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "k=1/ratio\n",
-      "e1=v/3**0.5\n",
-      "e2=k*e1\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "pcr=3*i2**2*r\n",
-      "pm=pcr*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "n=ns*(1-sm)\n",
-      "e3=sm*e2\n",
-      "\n",
-      "#result\n",
-      "print \"load torque=\",tg/9.81,\"kg-m\"\n",
-      "print \"speed at maximum torque=\",n,\"rpm\"\n",
-      "print \"rotor emf at max torque=\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load torque= 4.26478644041 kg-m\n",
-        "speed at maximum torque= 1333.33333333 rpm\n",
-        "rotor emf at max torque= 8.06457518868 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 88
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.39(b), Page Number:1290"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "p=4\n",
-      "i=10#A\n",
-      "pf=0.86\n",
-      "loss=0.05\n",
-      "cu_r=0.04\n",
-      "m_loss=0.03\n",
-      "\n",
-      "#calculation\n",
-      "input_m=3**0.5*v*i*pf\n",
-      "loss_s=loss*input_m\n",
-      "input_r=input_m-loss_s\n",
-      "cu_lossr=cu_r*input_r\n",
-      "mec_loss=m_loss*input_r\n",
-      "output_shaft=input_r-cu_lossr-mec_loss\n",
-      "s=cu_lossr/input_r\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "wr=2*3.14*n/60\n",
-      "output_r=input_r-cu_lossr\n",
-      "tr=output_r/wr\n",
-      "tin=output_shaft/wr\n",
-      "\n",
-      "#result\n",
-      "print \"slip=\",s*100,\"%\"\n",
-      "print \"rotor speed=\",n,\"rpm\"\n",
-      "print \"torque developed in the rotor=\",tr,\"Nw-m\"\n",
-      "print \"shaft torque=\",tin,\"Nw-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip= 4.0 %\n",
-        "rotor speed= 1440.0 rpm\n",
-        "torque developed in the rotor= 36.0531340072 Nw-m\n",
-        "shaft torque= 34.9264735695 Nw-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 91
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.40, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440.0#V\n",
-      "p=40.0\n",
-      "f=50.0#Hz\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "ratio=3.5\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "k=1/ratio\n",
-      "e2=k*e1\n",
-      "er=s*e2\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=er/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "output=cu_loss*(1-s)/s\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(x*sm)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "input_r=cu_loss/sm\n",
-      "\n",
-      "#result\n",
-      "print \"gross output at 5% slip=\",output,\"W\"\n",
-      "print \"maximum torque=\",input_r,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross output at 5% slip= 6242.77652849 W\n",
-        "maximum torque= 8780.04535147 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.41, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "loss=0.025\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "pw=loss*pout*1000\n",
-      "pm=pout*1000+pw\n",
-      "cu_loss=s*pm/(1-s)\n",
-      "p2=cu_loss/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tsh=9.55*pout*1000/n\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor cu loss=\",cu_loss,\"W\"\n",
-      "print \"rotor input=\",p2,\"W\"\n",
-      "print \"shaft torque=\",tsh,\"N-m\"\n",
-      "print \"gross electromagnetic torque=\",tg,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor cu loss= 796.510416667 W\n",
-        "rotor input= 19912.7604167 W\n",
-        "shaft torque= 123.685763889 N-m\n",
-        "gross electromagnetic torque= 126.777907986 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 109
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.42, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "f=50.0#Hz\n",
-      "n=710#rpm\n",
-      "load=35#kW\n",
-      "loss=1200#W\n",
-      "loss_r=600#W\n",
-      "\n",
-      "#calculation\n",
-      "p2=load*1000-loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_loss=s*p2\n",
-      "pm=p2-cu_loss\n",
-      "tg=9.55*pm/n\n",
-      "pout=pm-loss_r\n",
-      "tsh=9.55*pout/n\n",
-      "\n",
-      "#result\n",
-      "print \"rotor copper loss=\",cu_loss/1000,\"kW\"\n",
-      "print \"gross torque=\",tg,\"N-m\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"net torque=\",tsh,\"N-m\"\n",
-      "print \"mechanical power output=\",pout,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "rotor copper loss= 1.80266666667 kW\n",
-        "gross torque= 430.386666667 N-m\n",
-        "mechanical power= 31997.3333333 W\n",
-        "net torque= 422.316244131 N-m\n",
-        "mechanical power output= 31397.3333333 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 113
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.43, Page Number:1292"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "s=0.04\n",
-      "tsh=149.3#N-m\n",
-      "loss=200#W\n",
-      "cu_loss=1620#W\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "pout=tsh*2*3.14*(n/60)\n",
-      "output=pout+loss\n",
-      "p2=output*ns/n\n",
-      "cu_lossr=p2-output\n",
-      "p1=p2+cu_loss\n",
-      "efficiency=pout*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"output power=\",pout/1000,\"kW\"\n",
-      "print \"rotor cu loss=\",cu_lossr,\"W\"\n",
-      "print \"the efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output power= 15.001664 kW\n",
-        "rotor cu loss= 633.402666667 W\n",
-        "the efficiency= 85.9444669361 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 116
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.44, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pout=18.65#kW\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "n=960#rpm\n",
-      "i2=35#A\n",
-      "loss=1#kW\n",
-      "\n",
-      "#calculation\n",
-      "pm=pout+loss\n",
-      "ns=120*f/p\n",
-      "s=(ns-n)/ns\n",
-      "cu_lossr=pm*s*1000/(1-s)\n",
-      "r2=cu_lossr/(3*i2**2)\n",
-      "\n",
-      "#result\n",
-      "print \"resistane per phase=\",r2,\"ohm/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistane per phase= 0.222789115646 ohm/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 120
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.45, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "sf=Symbol('sf')\n",
-      "v=400#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "r=0.01#ohm\n",
-      "x=0.1#ohm\n",
-      "ratio=4\n",
-      "\n",
-      "#calculation\n",
-      "e1=v/3**0.5\n",
-      "e2=e1/ratio\n",
-      "sm=r/x\n",
-      "ns=120*f/p\n",
-      "tmax=(3/(2*3.14*25))*(e2**2/(2*x))\n",
-      "a=r/x\n",
-      "sf=solve(0.5*(a**2+sf**2)-2*a*sf,sf)\n",
-      "n=ns*(1-sf[0])\n",
-      "tf=tmax/2\n",
-      "output=2*3.14*n*tf/60\n",
-      "\n",
-      "#result\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"full load slip=\",sf[0]\n",
-      "print \"power output=\",output,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 318.47133758 N-m\n",
-        "full load slip= 0.0267949192431123\n",
-        "power output= 24330.1270189222 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 129
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.46, Page Number:1291"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "v=200.0#V\n",
-      "r=0.1#ohm\n",
-      "x=0.9#ohm\n",
-      "k=0.67\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "e1=v/3**0.5\n",
-      "e2=e1*k\n",
-      "z=(r**2+(s*x)**2)**0.5\n",
-      "i2=s*e2/z\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "sm=r/x\n",
-      "er=sm*e2\n",
-      "zr=(r**2+(sm*x)**2)**0.5\n",
-      "i2=er/zr\n",
-      "cu_lossr=3*i2**2*r\n",
-      "output=cu_lossr*(1-sm)/sm\n",
-      "n=(1-sm)*ns\n",
-      "tmax=9.55*output/n\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"maximum torque=\",tmax,\"N-m\"\n",
-      "print \"speed at max torque=\",n,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 40.4815391879 N-m\n",
-        "maximum torque= 63.511037037 N-m\n",
-        "speed at max torque= 1333.33333333 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 143
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.47, Page Number:1293"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "r=0.015#ohm\n",
-      "x=0.09#ohm\n",
-      "f=50#Hz\n",
-      "s=0.04\n",
-      "p=4\n",
-      "e2=110#V\n",
-      "\n",
-      "#calculations\n",
-      "z=(r**2+x**2)**0.5\n",
-      "pf=r/z\n",
-      "xr=s*x\n",
-      "zr=(r**2+xr**2)**0.5\n",
-      "pf2=r/zr\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "er=s*e2\n",
-      "i2=er/zr\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=cu_loss*(1-s)/s\n",
-      "tg=9.55*pm/n\n",
-      "\n",
-      "#result\n",
-      "print \"pf of motor at start=\",pf\n",
-      "print \"pf of motor at s=4%\",pf2\n",
-      "print \"full load torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf of motor at start= 0.164398987305\n",
-        "pf of motor at s=4% 0.972387301981\n",
-        "full load torque= 582.728189612 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 144
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.48, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6.0\n",
-      "f=50.0#Hz\n",
-      "tsh=162.84#N-m\n",
-      "c=90.0\n",
-      "t=20.36#N-m\n",
-      "loss=830.0#W\n",
-      "\n",
-      "#calculation\n",
-      "ns=120*f/p\n",
-      "fr=c/60\n",
-      "s=fr/f\n",
-      "n=ns*(1-s)\n",
-      "output=2*3.14*n*tsh/60\n",
-      "tg=tsh+t\n",
-      "p2=tg*ns/9.55\n",
-      "cu_lossr=s*p2\n",
-      "p1=p2+cu_lossr\n",
-      "efficiency=output*100/p1\n",
-      "\n",
-      "#result\n",
-      "print \"motor output=\",output,\"W\"\n",
-      "print \"cu loss=\",cu_lossr,\"W\"\n",
-      "print \"motor input\",p1,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "motor output= 16532.6024 W\n",
-        "cu loss= 575.497382199 W\n",
-        "motor input 19758.7434555 W\n",
-        "efficiency= 83.6723369441 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 146
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.49, Page Number:1294"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=18.65#kW\n",
-      "v=420.0#V\n",
-      "p=6\n",
-      "f=50.0#Hz\n",
-      "r=1.0#ohm\n",
-      "z=complex(0.25,0.75)\n",
-      "zr=complex(0.173,0.52)\n",
-      "v1=420.0#V\n",
-      "v2=350.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=v2/v1\n",
-      "r02=zr.real+k**2*z.real\n",
-      "x02=zr.imag+k**2*z.imag\n",
-      "z02=((r+r02)**2+x02**2)**0.5\n",
-      "i2=v2/(3**0.5*z02)\n",
-      "cu_loss=i2**2*(r+zr.real)\n",
-      "p2=cu_loss*3\n",
-      "ns=120*f/p\n",
-      "tst=9.55*p2/(ns*9.81)\n",
-      "#result\n",
-      "print \"torque=\",tst,\"kg-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 48.2909354778 kg-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.50, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=8\n",
-      "load=37.3#ohm\n",
-      "v=280#V\n",
-      "f=50.0#Hz\n",
-      "i=200#A\n",
-      "pf=0.25\n",
-      "r=0.15#ohm\n",
-      "k=1.0/3\n",
-      "#calculation\n",
-      "wsc=2*v*i*pf\n",
-      "power_phase=v*i*pf\n",
-      "R=power_phase/i**2\n",
-      "r2_=R-r\n",
-      "r2=k**2*r2_\n",
-      "p2=3*i**2*r2_\n",
-      "ns=120*f/p\n",
-      "t=9.55*p2/ns\n",
-      "\n",
-      "#result\n",
-      "print \"resistance perphaseof therotor winding=\",r2,\"ohm\"\n",
-      "print \"startingtorque=\",t,\"N-m\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistance perphaseof therotor winding= 0.0222222222222 ohm\n",
-        "startingtorque= 305.6 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.51, Page Number:1295"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ratios=1.6\n",
-      "ratiom=2.0\n",
-      "sf=0.01\n",
-      "sb=0.04\n",
-      "#calculation\n",
-      "i=(ratios/sf)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"slip at full load=\",sf\n",
-      "print \"slip at maximum torque=\",sb\n",
-      "print \"rotor current=\",i"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "slip at full load= 0.01\n",
-        "slip at maximum torque= 0.04\n",
-        "rotor current= 12.6491106407\n"
-       ]
-      }
-     ],
-     "prompt_number": 159
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.52, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=200#km/h\n",
-      "f=100#Hz\n",
-      "\n",
-      "#calculation\n",
-      "w=v*5.0/18/(2*f)\n",
-      "\n",
-      "#result\n",
-      "print \"pole pitch=\",w*1000,\"mm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pole pitch= 277.777777778 mm\n"
-       ]
-      }
-     ],
-     "prompt_number": 162
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.53, Page Number:1297"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "w=6#mm\n",
-      "f=25#Hz\n",
-      "p=6#kW\n",
-      "loss=1.2#kW\n",
-      "v=2.4#m/s\n",
-      "\n",
-      "#calculation\n",
-      "vs=2*f*w/100\n",
-      "s=(vs-v)/vs\n",
-      "p2=p-loss\n",
-      "pcr=s*p2\n",
-      "pm=p2-pcr\n",
-      "f=p2*1000/vs\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous speed=\",vs,\"m/s\"\n",
-      "print \"slip=\",s\n",
-      "print \"cu loss=\",pcr,\"kW\"\n",
-      "print \"mechanical power=\",pm,\"kW\"\n",
-      "print \"thrust=\",f/1000,\"kN\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous speed= 3 m/s\n",
-        "slip= 0.2\n",
-        "cu loss= 0.96 kW\n",
-        "mechanical power= 3.84 kW\n",
-        "thrust= 1.6 kN\n"
-       ]
-      }
-     ],
-     "prompt_number": 163
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.54, Page Number:1304"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=0.12\n",
-      "r=0.08#ohm/phase\n",
-      "pg=9000.0#W\n",
-      "\n",
-      "#calculations\n",
-      "rl=r*(1/s-1)\n",
-      "v=(pg*rl/3)**0.5\n",
-      "il=v/rl\n",
-      "\n",
-      "#result\n",
-      "print \"load resistance=\",rl,\"ohm\"\n",
-      "print \"load voltage=\",v,\"V\"\n",
-      "print \"load current=\",il,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load resistance= 0.586666666667 ohm\n",
-        "load voltage= 41.9523539268 V\n",
-        "load current= 71.5096941934 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 166
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.55, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "p=4\n",
-      "r1=0.15#ohm\n",
-      "x1=0.45#ohm\n",
-      "r2_=0.12#ohm\n",
-      "x2_=0.45#ohm\n",
-      "xm=complex(0,28.5)#ohm\n",
-      "s=0.04\n",
-      "#calculations\n",
-      "rl_=r2_*(1/s-1)\n",
-      "i2_=(v/3**0.5)/complex(r1+rl_,x1)\n",
-      "i0=(v/3**0.5)/xm\n",
-      "i1=i0+i2_\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "\n",
-      "#result\n",
-      "print \"stator current=\",i1,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stator current= (74.5730253701-19.1783634605j) A\n",
-        "power factor= 0.968485280755\n"
-       ]
-      }
-     ],
-     "prompt_number": 177
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.56, Page Number:1305"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=220#V\n",
-      "p=4\n",
-      "f=50#Hz\n",
-      "power=3.73#kW\n",
-      "r1=0.45#ohm\n",
-      "x1=0.8#ohm\n",
-      "r2_=0.4#ohm\n",
-      "x2_=0.8#ohm\n",
-      "b0=-1.0/30\n",
-      "loss=50#W\n",
-      "lossr=150#W\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "zab=complex(30*complex(r2_/s,x2_))/complex(r2_/s,x2_-1/b0)\n",
-      "z01=complex(r1,x1)+zab\n",
-      "vph=v/3**0.5\n",
-      "i1=v1/z01\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i1.real**2*zab.real\n",
-      "pm=(1-s)*p2\n",
-      "ns=120*f/p\n",
-      "n=ns*(1-s)\n",
-      "tg=9.55*pm/n\n",
-      "power_o=pm-lossr\n",
-      "cu_loss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_loss+cu_lossr+lossr\n",
-      "efficiency=power_o/(power_o+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"input current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"air gap power=\",p2,\"W\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"electro magnetic torque=\",tg,\"N-m\"\n",
-      "print \"output power=\",power_o,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "input current= (21.9914486234+42.6194245913j) A\n",
-        "pf= 0.45854949826\n",
-        "air gap power= 5173.46132109 W\n",
-        "mechanical power= 4966.52286825 W\n",
-        "electro magnetic torque= 32.9377037443 N-m\n",
-        "output power= 4816.52286825 W\n",
-        "efficiency= 81.9644851937 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.57, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "load=37.3#kW\n",
-      "r1=0.1#ohm\n",
-      "x1=0.4#ohm\n",
-      "r2_=0.15#ohm\n",
-      "x2_=0.44#ohm\n",
-      "loss=1250#W\n",
-      "lossr=1000#W\n",
-      "i=20#A\n",
-      "pf=0.09\n",
-      "s=0.03\n",
-      "\n",
-      "#calculation\n",
-      "v1=v/3**0.5\n",
-      "i2_=v1/complex(r1+r2_/s,x1+x2_)\n",
-      "i1=i2_+complex(1.78,19.9)\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=3*i2_.real**2*r2_/s\n",
-      "ns=120*f/p\n",
-      "tg=9.55*p2/ns\n",
-      "pm=p2*(1-s)\n",
-      "pout=pm-1000\n",
-      "cu_losss=3*i1.real**2*r1\n",
-      "cu_lossr=s*p2\n",
-      "total_loss=loss+cu_losss+cu_lossr+lossr\n",
-      "efficiency=pout/(pout+total_loss)\n",
-      "\n",
-      "#result\n",
-      "print \"line current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"electromagnetic torque=\",tg,\"N-m\"\n",
-      "print \"output=\",pout,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line current= (50.2750367599+11.9125821807j) A\n",
-        "pf= 0.973057118792\n",
-        "electromagnetic torque= 224.593900377 N-m\n",
-        "output= 33218.2329894 W\n",
-        "efficiency= 89.0932246577 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 186
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.58, Page Number:1306"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.06,0.2)\n",
-      "zr=complex(0.06,0.22)\n",
-      "\n",
-      "#calculation\n",
-      "r01=z.real+zr.real\n",
-      "x01=z.imag+zr.imag\n",
-      "z01=(r01**2+x01**2)**0.5\n",
-      "s=z.real/(z.real+z01)\n",
-      "v1=v/3**0.5\n",
-      "pmax=3*v1**2/(2*(r01+z01))\n",
-      "\n",
-      "#result\n",
-      "print \"maximum gross power=\",pmax,\"W\"\n",
-      "print \"slip=\",s"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum gross power= 143676.459572 W\n",
-        "slip= 0.120771344025\n"
-       ]
-      }
-     ],
-     "prompt_number": 188
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.59, Page Number:1307"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v1=115#V\n",
-      "f=60.0#Hz\n",
-      "p=6\n",
-      "z=complex(0.07,0.3)\n",
-      "zr=complex(0.08,0.3)\n",
-      "gd=0.022#mho\n",
-      "bo=0.158#mho\n",
-      "s=0.02\n",
-      "\n",
-      "#calculation\n",
-      "rl_=1/bo*(1/s-1)\n",
-      "z=complex(z.real+zr.real+rl_,0.6)\n",
-      "v=v1/3**0.5\n",
-      "i2=complex(16,-2.36)\n",
-      "io=v*complex(gd,-bo)\n",
-      "i1=io+i2\n",
-      "pf=math.cos(math.atan(i1.imag/i1.real))\n",
-      "pg=3*abs(i2)**2*rl_/100\n",
-      "ns=120*f/p\n",
-      "n=(1-s)*ns\n",
-      "tg=9.55*pg/n\n",
-      "p2=3**0.5*v1*abs(i1)*pf\n",
-      "efficiency=pg*100/p2\n",
-      "\n",
-      "#result\n",
-      "print \"secondary current=\",i2,\"A\"\n",
-      "print \"primary current=\",i1,\"A\"\n",
-      "print \"pf=\",pf\n",
-      "print \"power output=\",pg,\"W\"\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "print \"input=\",p2,\"W\"\n",
-      "print \"efficiency=\",efficiency,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "secondary current= (16-2.36j) A\n",
-        "primary current= (17.460696181-12.8504543912j) A\n",
-        "pf= 0.805393212665\n",
-        "power output= 2433.59058228 W\n",
-        "torque= 19.7625765823 N-m\n",
-        "input= 3477.92348593 W\n",
-        "efficiency= 69.9725164204 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 34.60, Page Number:1308"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=400#V\n",
-      "z=complex(0.4,1)\n",
-      "zr=complex(0.6,1)\n",
-      "zm=complex(10,50)\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "sm=zr.real/(z.real**2+(z.imag+zr.imag)**2)**0.5\n",
-      "v1=v/3**0.5\n",
-      "i2=v1/((z.real+zr.real)**2+(zr.imag+z.imag)**2)**0.5\n",
-      "tgmax=3*i2**2*z.real*60/(sm*2*3.14*1500)\n",
-      "#result\n",
-      "print \"maximum torque=\",tgmax,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum torque= 277.144160399 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 208
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_1.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_1.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_2.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_2.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_3.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_3.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_4.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_4.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_5.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_5.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_6.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_6.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_7.ipynb
deleted file mode 100755
index 1c89c3bd..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter35_7.ipynb
+++ /dev/null
@@ -1,1220 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:87ef53401e46d15eef2e50d8ed392f8c9e3784abe371e55cb0923dbffffe7b33"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 35: Computations and Circle Diagrams"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.1, Page Number:1316"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=10#A\n",
-      "p=450#W\n",
-      "v=110#V\n",
-      "r=0.05#ohm\n",
-      "loss=135#w\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=3*i**2*r\n",
-      "core_loss=p-loss-cu_loss\n",
-      "volt=v/math.sqrt(3)\n",
-      "g=core_loss/(3*(v/math.sqrt(3))**2)\n",
-      "y=i*math.sqrt(3)/v\n",
-      "b=math.sqrt(y**2-g**2)\n",
-      "\n",
-      "#result\n",
-      "print \"exciting conductance=\",g,\"seimens/phase\"\n",
-      "print \"susceptance/phase=\",b,\"seimens/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "exciting conductance= 0.0247933884298 seimens/phase\n",
-        "susceptance/phase= 0.155494939853 seimens/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.2, Page Number:1317"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=110.0#V\n",
-      "i=25.0#A\n",
-      "v2=30.0#V\n",
-      "inpt=440.0#W\n",
-      "loss=40.0#W\n",
-      "r=0.1#ohm\n",
-      "ratio=1.6\n",
-      "\n",
-      "#calculations\n",
-      "vs=v2/math.sqrt(3)\n",
-      "z01=vs/i\n",
-      "losses=inpt-loss\n",
-      "r01=losses/(3*i**2)\n",
-      "x01=math.sqrt(z01**2-r01**2)\n",
-      "dc_r=r/2.0\n",
-      "ac_r=dc_r*ratio\n",
-      "effective_r=r01-ac_r\n",
-      "\n",
-      "#result\n",
-      "print \"x01=\",x01,\"ohm\"\n",
-      "print \"r1=\",ac_r,\"ohm\"\n",
-      "print \"r2=\",effective_r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "x01= 0.659157711696 ohm\n",
-        "r1= 0.08 ohm\n",
-        "r2= 0.133333333333 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.10, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=1/4.0\n",
-      "slip=3.0\n",
-      "ratio2=4.0\n",
-      "\n",
-      "#calculations\n",
-      "K=math.sqrt(ratio/((ratio2**2)*0.01*slip))\n",
-      "\n",
-      "#result\n",
-      "print \"Percentage Tapping=\",K*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Percentage Tapping= 72.1687836487 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.11, Page Number:1333"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=14.92#kW\n",
-      "v1=400#V\n",
-      "n=950#rpm\n",
-      "f=50.0#Hz\n",
-      "v2=400#V\n",
-      "ratio=1.8\n",
-      "i=30#A\n",
-      "\n",
-      "#calculations\n",
-      "v=v1/math.sqrt(ratio)\n",
-      "If=6*v*i/v1\n",
-      "K=v/v1\n",
-      "kisc=K**2*6*i\n",
-      "ts_tf=(1/6.0)*6**2*(f/1000.0)\n",
-      "\n",
-      "#result\n",
-      "print \"a)voltage=\",v,\"V\"\n",
-      "print \"b)current=\",If,\"A\"\n",
-      "print \"c)line current=\",kisc,\"A\"\n",
-      "print \"d)percentage=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)voltage= 298.142397 V\n",
-        "b)current= 134.16407865 A\n",
-        "c)line current= 100.0 A\n",
-        "d)percentage= 30.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 22
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.12, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "ratio=5.0\n",
-      "per=5\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(ratio/3)\n",
-      "tst_tf=(3.0/5)*5**2*0.01*per*100\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",tst_tf,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 75.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 29
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.13, Page Number:1334"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V\n",
-      "per=3.5\n",
-      "v2=92.0#V\n",
-      "\n",
-      "#calculations\n",
-      "k=math.sqrt(2/(v/v2))\n",
-      "ts_tf=k**2*(v/v2)**2*0.01*per\n",
-      "\n",
-      "#result\n",
-      "print \"auto-transformation ratio=\",ts_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-transformation ratio= 30.4347826087 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.14, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=12.0#kW\n",
-      "v=440.0#V\n",
-      "efficiency=0.85\n",
-      "pf=0.8\n",
-      "i=45.0#A\n",
-      "v2=220.0#V\n",
-      "\n",
-      "#calculations\n",
-      "isc=i*v/v2\n",
-      "if_=load*1000/(efficiency*math.sqrt(3)*pf*v)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "ratio=ist/if_\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 2.244\n"
-       ]
-      }
-     ],
-     "prompt_number": 34
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.15, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "i=60.0#A\n",
-      "n1=940.0#rpm\n",
-      "t=150.0#N-m\n",
-      "i2=300.0#A\n",
-      "\n",
-      "#calculations\n",
-      "sf=(1000-n1)/1000\n",
-      "tst=t*(i2/i)**2*sf\n",
-      "s_i=i2/3\n",
-      "sd_tst=tst/3\n",
-      "\n",
-      "#result\n",
-      "print \"Starting torque=\",tst,\"N-m\"\n",
-      "print\"when star/delta is used:\"\n",
-      "print \"starting current=\",s_i,\"A\"\n",
-      "print \"starting torque=\",sd_tst,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Starting torque= 225.0 N-m\n",
-        "when star/delta is used:\n",
-        "starting current= 100.0 A\n",
-        "starting torque= 75.0 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.16, Page Number:1336"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "tapping=70.7\n",
-      "ratio=6.0\n",
-      "slip=4.0\n",
-      "\n",
-      "#calculation\n",
-      "tst_tf=(1.0/3.0)*ratio**2.0*slip*0.01\n",
-      "tst_tf2=(1.0/2)*ratio**2.0*slip*0.01\n",
-      "\n",
-      "#result\n",
-      "print \"star-delta switch:starting torque=\",tst_tf*100,\"%\"\n",
-      "print \"auto-transformer switch:starting torque=\",tst_tf2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "star-delta switch:starting torque= 48.0 %\n",
-        "auto-transformer switch:starting torque= 72.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 48
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.17, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=11.2#W\n",
-      "f=50.0#Hz\n",
-      "v=400.0#V\n",
-      "n=960.0#rpm\n",
-      "i=86.4#A\n",
-      "efficiency=0.88\n",
-      "pf=0.85\n",
-      "\n",
-      "#calculations\n",
-      "isc=i/math.sqrt(3)\n",
-      "ist=isc/math.sqrt(3)\n",
-      "il=load*1000/(efficiency*pf*math.sqrt(3)*v)\n",
-      "iph=il/math.sqrt(3)\n",
-      "tst_tf=(ist*math.sqrt(3)/il)**2*0.05\n",
-      "\n",
-      "#result\n",
-      "print \"starting torque=\",tst_tf*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting torque= 26.6369577796 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.18, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "output=10.0#kW\n",
-      "v=400.0#V\n",
-      "pf=0.85\n",
-      "efficiency=0.88\n",
-      "v2=200.0#V\n",
-      "i=40.0#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(efficiency*math.sqrt(3)*v*pf)\n",
-      "isc=i*v/v2\n",
-      "iscp=isc/math.sqrt(3)\n",
-      "ist=iscp/math.sqrt(3)\n",
-      "ratio=ist/il\n",
-      "\n",
-      "#result\n",
-      "print \"ratio=\",ratio"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "ratio= 1.23388000387\n"
-       ]
-      }
-     ],
-     "prompt_number": 53
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.19, Page Number:1337"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.73*1000#W\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "slip=4.5\n",
-      "t=250.0\n",
-      "i=650.0\n",
-      "tap=60.0\n",
-      "\n",
-      "#calculation\n",
-      "il=i/3\n",
-      "im=i/3\n",
-      "tst=t/3\n",
-      "ilm=(tap/100)**2*i\n",
-      "imk=(tap/100)*i\n",
-      "tstk=(tap/100)**2*t\n",
-      "\n",
-      "#result\n",
-      "print \"star/delta:\"\n",
-      "print \"line current=\",il,\"%\"\n",
-      "print \"motor current=\",im,\"%\"\n",
-      "print \"starting torque=\",tst,\"%\"\n",
-      "print \"60% taps:\"\n",
-      "print \"line current=\",ilm,\"%\"\n",
-      "print \"motor current=\",imk,\"%\"\n",
-      "print \"starting torque=\",tstk,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " star/delta:\n",
-        "line current= 216.666666667 %\n",
-        "motor current= 216.666666667 %\n",
-        "starting torque= 83.3333333333 %\n",
-        "60% taps:\n",
-        "line current= 234.0 %\n",
-        "motor current= 390.0 %\n",
-        "starting torque= 90.0 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.20, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=180.0\n",
-      "flt=35.0\n",
-      "tap=75.0\n",
-      "\n",
-      "#calculations\n",
-      "isc=load*3.0/100\n",
-      "isck=tap**2*isc/100\n",
-      "sf=flt*3\n",
-      "tst_tf=tap**2*sf/100\n",
-      "#result\n",
-      "print \"starting current=\",isck,\"%\"\n",
-      "print \"starting torque=\",tst_tf/100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "starting current= 303.75 %\n",
-        "starting torque= 59.0625 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 68
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.21, Page Number:1338"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "w=7.46#kW\n",
-      "ic=1.7\n",
-      "t=35.0\n",
-      "ratio=60.0\n",
-      "\n",
-      "#calculations\n",
-      "sf=t*3/100\n",
-      "il1=ic*3\n",
-      "tst=(ratio/1000)**2*sf*10000\n",
-      "il2=(ratio/100)*3*ic\n",
-      "\n",
-      "#results\n",
-      "print \"auto-starter:\"\n",
-      "print \"line-current=\",il1,\"%\"\n",
-      "print \"torque=\",tst,\"%\"\n",
-      "print \"voltage decreased to 60%\"\n",
-      "print \"line-current\",il2,\"%\"\n",
-      "print \"torque=\",tst,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "auto-starter:\n",
-        "line-current= 5.1 %\n",
-        "torque= 37.8 %\n",
-        "voltage decreased to 60%\n",
-        "line-current 3.06 %\n",
-        "torque= 37.8 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.22, Page Number:1342"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "slip=2.0\n",
-      "r=0.02#ohm\n",
-      "n=6.0\n",
-      "#calculations\n",
-      "smax=r2=slip/100.0\n",
-      "R1=r2/smax\n",
-      "K=math.pow(smax,1.0/5)\n",
-      "R2=K*R1\n",
-      "R3=K*R2\n",
-      "R4=K*R3\n",
-      "R5=K*R4\n",
-      "p1=R1-R2\n",
-      "p2=R2-R3\n",
-      "p3=R3-R4\n",
-      "p4=R4-R5\n",
-      "p5=R5-r2\n",
-      "\n",
-      "#result\n",
-      "print \"resistances of various starter sections:\"\n",
-      "print \"p1=\",p1,\"ohm\"\n",
-      "print \"p2=\",p2,\"ohm\"\n",
-      "print \"p3=\",p3,\"ohm\"\n",
-      "print \"p4=\",p4,\"ohm\"\n",
-      "print \"p5=\",p5,\"ohm\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "resistances of various starter sections:\n",
-        "p1= 0.542694948073 ohm\n",
-        "p2= 0.248177141409 ohm\n",
-        "p3= 0.113492660539 ohm\n",
-        "p4= 0.0519007670213 ohm\n",
-        "p5= 0.0237344829577 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 107
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.23, Page Number:1345"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "primary=complex(1,3)\n",
-      "outer=complex(3,1)\n",
-      "inner=complex(0.6,5)\n",
-      "s=4\n",
-      "outer2=complex(3/(s*0.01),1)\n",
-      "inner2=complex(0.6/(s*0.01),5)\n",
-      "v=440#V\n",
-      "\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z01=primary+1/((1/outer)+(1/inner))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=1: torque=\",torque,\"synch watt\"\n",
-      "\n",
-      "#s=4\n",
-      "z01=primary+1/((1/outer2)+(1/inner2))\n",
-      "current_per_phase=v/abs(z01)\n",
-      "torque=3*current_per_phase**2*(z01.real-1)\n",
-      "\n",
-      "print \"s=4: torque=\",torque,\"synch watt\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1: torque= 35065.3642462 synch watt\n",
-        "s=4: torque= 32129.9449695 synch watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.24, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inner=complex(0.4,2)\n",
-      "outer=complex(2,0.4)\n",
-      "s=5\n",
-      "inner2=complex(0.4/(s*0.01),2)\n",
-      "outer2=complex(2/(s*0.01),0.4)\n",
-      "print \n",
-      "#calculations\n",
-      "#s=1\n",
-      "zi=abs(inner)\n",
-      "zo=abs(outer)\n",
-      "r_ratio=inner.imag/outer.imag\n",
-      "to_ti=r_ratio*(zo/zi)**2\n",
-      "print \"Ratio of torques when s=1:\",to_ti\n",
-      "\n",
-      "#s=5\n",
-      "zi=abs(inner2)\n",
-      "zo=abs(outer2)\n",
-      "print zi\n",
-      "r_ratio=inner2.imag/outer2.imag\n",
-      "to_ti=r_ratio*(zi/zo)**2\n",
-      "\n",
-      "print \"Ratio of torques when s=5:\",to_ti"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "\n",
-        "Ratio of torques when s=1: 5.0\n",
-        "8.24621125124\n",
-        "Ratio of torques when s=5: 0.212478752125\n"
-       ]
-      }
-     ],
-     "prompt_number": 37
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.25, Page Number:1346"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s=5\n",
-      "zi=complex(0.05,0.4)\n",
-      "zo=complex(0.5,0.1)\n",
-      "v=100#V\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=1:torque=\",t,\"synch watts\"\n",
-      "\n",
-      "#s=0.01\n",
-      "zi=complex(0.05/(s*0.01),0.4)\n",
-      "zo=complex(0.5/(s*0.01),0.1)\n",
-      "z=zo*zi/(zo+zi)\n",
-      "r2=z.real\n",
-      "z=abs(z)\n",
-      "i2=v/z\n",
-      "t=i2**2*r2\n",
-      "print \"s=5:torque=\",t,\"synch watts\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 22307.6923077 synch watts\n",
-        "s=5:torque= 9620.58966517 synch watts\n"
-       ]
-      }
-     ],
-     "prompt_number": 43
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.27, Page Number:1347"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "zo=complex(1,0)\n",
-      "zi=complex(0.15,3)\n",
-      "v=250#V\n",
-      "n=1000#rpm\n",
-      "\n",
-      "#calculations\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "stator=complex(0.25,3.5)\n",
-      "z01=z2+stator\n",
-      "i=complex(v,0)/z01\n",
-      "i=abs(i)\n",
-      "cu_loss=i**2*z01.real\n",
-      "T=cu_loss*3/(2*math.pi*(n/60))\n",
-      "#result\n",
-      "print \"torque=\",T,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 135.560320318 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.28, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z1=complex(1,2.8)\n",
-      "zo=complex(3,1)\n",
-      "zi=complex(0.5,5)\n",
-      "v=440#V\n",
-      "s=0.04\n",
-      "\n",
-      "#calculations\n",
-      "#s=1\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "\n",
-      "print \"s=1:torque=\",t,\"synch. watt\"\n",
-      "\n",
-      "#s=0.04\n",
-      "zo=complex(3.0/s,1.0)\n",
-      "zi=complex(0.5/s,5.0)\n",
-      "z2=zo*zi/(zo+zi)\n",
-      "z01=z1+z2\n",
-      "i2=v/z01\n",
-      "r2=z2.real\n",
-      "t=abs(i2)**2*r2\n",
-      "print \"s=4:torque=\",t,\"synch. watt\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "s=1:torque= 12388.3258184 synch. watt\n",
-        "s=4:torque= 11489.1141244 synch. watt\n"
-       ]
-      }
-     ],
-     "prompt_number": 58
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.29, Page Number:1351"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "r=0.30#ohm\n",
-      "n1=1440.0#rpm\n",
-      "n2=1320.0#rpm\n",
-      "ns=120.0*f/4.0\n",
-      "#calculations\n",
-      "s1=(ns-n1)/ns\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.6 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.30, Page Number:1348"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "s=0.03\n",
-      "ratio=10.0\n",
-      "r=0.2\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/6\n",
-      "s1=s\n",
-      "n1=ns*(1-s1)\n",
-      "n2=n1-10*n1/100\n",
-      "s2=(ns-n2)/ns\n",
-      "r=s2*r/s1-r\n",
-      "\n",
-      "#result\n",
-      "print \"external resistance=\",r,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "external resistance= 0.646666666667 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 61
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.31, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#Variable declaration\n",
-      "f=50#Hz\n",
-      "s=0.02\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "n=(1-s)*nsc\n",
-      "nsa=120*f/6\n",
-      "sa=(nsa-n)/nsa\n",
-      "f_=sa*f\n",
-      "n_=(120*f_)/4\n",
-      "sb=(n_-n)/n_\n",
-      "f__=sb*f_\n",
-      "\n",
-      "#resu;t\n",
-      "print \"f_=\",f_,\"Hz\"\n",
-      "print \"f_ _=\",f__,\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "f_= 20.6 Hz\n",
-        "f_ _= 1.0 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.32, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "f2=1.0#Hz\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "s=f2/f\n",
-      "n=nsc-s*nsc\n",
-      "nsa=120*f/4\n",
-      "sa=(nsa-n)/nsa\n",
-      "f1=sa*f\n",
-      "n2=120*f1/6\n",
-      "sb=(n2-n)/n2\n",
-      "\n",
-      "#result\n",
-      "print \"sa=\",sa*100,\"%\"\n",
-      "print \"sb=\",sb*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "sa= 60.8 %\n",
-        "sb= 3.28947368421 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.33, Page Number:1354"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=74.6#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 29.84 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 79
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 35.34, Page Number:1355"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "load=25#kW\n",
-      "\n",
-      "#calculations\n",
-      "nsc=120*f/10\n",
-      "output=load*4/10\n",
-      "\n",
-      "#result\n",
-      "print \"speed of set=\",nsc,\"rpm\"\n",
-      "print \"electric power transferred=\",output,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "speed of set= 600 rpm\n",
-        "electric power transferred= 10 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 78
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_1.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_1.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_2.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_2.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_3.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_3.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_4.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_4.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_5.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_5.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_6.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_6.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_7.ipynb
deleted file mode 100755
index a28f10ba..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter36_7.ipynb
+++ /dev/null
@@ -1,393 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a362cd0373fe77cde513a2a109a4d7c05a5dbd87d086b1227fbc532438b6bbb6"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 36: Single-Phase Motors"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.1, Page Number:1374"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "v=110\n",
-      "f=60\n",
-      "s=0.05\n",
-      "\n",
-      "#calculations\n",
-      "xo=xm+x2\n",
-      "\n",
-      "zf=(((r2/s)*xm)/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "jf=(((r2/s)*(r2/s)+(x2*xo))/(((r2/s)*(r2/s))+(xo*xo)))*xm\n",
-      "Jf=math.degrees(math.atan(jf/zf))\n",
-      "\n",
-      "zb=(((r2/(2-s))*xm)/(((r2/s)*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "jb=(((r2/(2-s))*(r2/(2-s))+(x2*xo))/(((r2/(2-s))*(r2/(2-s)))+(xo*xo)))*xm\n",
-      "Jb=math.degrees(math.atan(jb/zb))\n",
-      "\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "z01=Z1+zf+zb\n",
-      "j01=jf+jb+J1\n",
-      "J01=math.degrees(math.atan(j01/z01))\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zb\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "output=t*(1-s)\n",
-      "\n",
-      "#result\n",
-      "print \"output = \",output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output =  206.798750547\n"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Example Number 36.2, Page Number:1375"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "p=185\n",
-      "v=110\n",
-      "f=50\n",
-      "s=0.05\n",
-      "R1=1.86\n",
-      "X1=2.56\n",
-      "Xo=53.5\n",
-      "R2=3.56\n",
-      "X2=2.56\n",
-      "Xm=53.5\n",
-      "cl=3.5#core loss\n",
-      "fl=13.5#friction loss\n",
-      "vf=(82.5/100)*v\n",
-      "ic=(cl*100)/vf\n",
-      "r1=R1/2\n",
-      "x1=X1/2\n",
-      "r2=R2/2\n",
-      "x2=X2/2\n",
-      "xm=Xm/2\n",
-      "rc=vf/ic\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "#motor 1\n",
-      "c=1/rc #conductance of corebranch\n",
-      "s=-(1/xm)#susceptance\n",
-      "a1=(r2/s)/(((r2/s)*r2/s)+(x2*x2))#admittance\n",
-      "a1j=-x2/(((r2/s)*r2/s)+(x2*x2))#admittance j\n",
-      "yf=c+a1\n",
-      "yfj=s+a1j\n",
-      "zf=(yf*yf)+(yfj*yfj)\n",
-      "zfr=yf/zf\n",
-      "zfj=yfj/zf\n",
-      "\n",
-      "#motor 2\n",
-      "a2=(r2/2-s)/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "a2j=-x2/(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "Z1=R1\n",
-      "J1=X1\n",
-      "yb=yf+a2\n",
-      "ybj=yfj+a2j\n",
-      "zb1=(yb*yb)+(ybj*ybj)\n",
-      "zbr=yb/zb1\n",
-      "zbj=ybj/zb1\n",
-      "z01=Z1+zf+zbr\n",
-      "z01j=J1+zfj+zbj\n",
-      "\n",
-      "i1=v/z01\n",
-      "vf=i1*zf\n",
-      "vb=i1*zbr\n",
-      "z3=math.sqrt(((r2/s)*(r2/s))+(x2*x2))\n",
-      "z5=math.sqrt(((r2/(2-s))*(r2/(2-s)))+(x2*x2))\n",
-      "\n",
-      "i3=vf/z3\n",
-      "i5=vb/z5\n",
-      "tf=(i3*i3*r2)/s\n",
-      "tb=t5=(i5*i5*r2)/(2-s)\n",
-      "t=tf-tb\n",
-      "watt=t*(1-s)\n",
-      "net_output=watt-fl\n",
-      "\n",
-      "#result\n",
-      "print \"Net output = \",net_output"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Net output =  -446.423232085\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.3, Page Number:1376"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "w=250\n",
-      "v=230\n",
-      "f=50\n",
-      "zm=4.5\n",
-      "zmj=3.7\n",
-      "za=9.5\n",
-      "zaj=3.5\n",
-      "\n",
-      "#calculations\n",
-      "zma=math.degrees(math.atan(zmj/zm))\n",
-      "ialeadv=90-zma\n",
-      "x=za*(math.tan(math.radians(ialeadv)))\n",
-      "xc=x+zaj\n",
-      "c=1000000/(xc*2*50*3.14)\n",
-      "\n",
-      "#result\n",
-      "print \"C= \",c,\" uf\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "C=  211.551875951  uf\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.4, Page Number:1393"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "\n",
-      "#variable declaration\n",
-      "\n",
-      "p=250\n",
-      "f=50\n",
-      "v=220\n",
-      "ndc=2000\n",
-      "ia=1\n",
-      "ra=20\n",
-      "la=0.4\n",
-      "\n",
-      "#calculations\n",
-      "ebdc=v-(ia*ra)\n",
-      "#ac\n",
-      "xa=2*3.14*f*la\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "nac=(ebac*ndc)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "pmech=ebac*ia\n",
-      "T=(pmech*9.55)/nac\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Torque= \",T,\" N-m\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1606.22922133  rpm\n",
-        "Torque=  0.955  N-m\n",
-        "Power Factor=  0.821013282424  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 30
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "Example Number 36.5, Page Number:1394"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "r=30\n",
-      "l=0.5\n",
-      "v=250\n",
-      "idc=0.8\n",
-      "ndc=2000\n",
-      "f=50\n",
-      "ia=0.8\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "xa=2*3.14*f*l\n",
-      "ra=r\n",
-      "ebac=-(ia*ra)+math.sqrt((v*v)-((ia*xa)*(ia*xa)))\n",
-      "ebdc=v-(r*idc)\n",
-      "nac=(ndc*ebac)/ebdc\n",
-      "cos_phi=(ebac+(ia*ra))/v\n",
-      "\n",
-      "#result\n",
-      "print \"Speed= \",nac,\" rpm\"\n",
-      "print \"Power Factor= \",cos_phi,\" lag\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Speed=  1700.52062383  rpm\n",
-        "Power Factor=  0.864635321971  lag\n"
-       ]
-      }
-     ],
-     "prompt_number": 36
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 36.6, Page Number:1396"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "f=50\n",
-      "a=30\n",
-      "w=8\n",
-      "v=220\n",
-      "v2=205\n",
-      "pole=4\n",
-      "\n",
-      "#calculations\n",
-      "\n",
-      "ns=(120*f)/pole\n",
-      "tsh=(9.55*w*1000)/ns\n",
-      "alpha=0.5*(math.degrees(math.asin((v*v*math.sin(math.radians(2*a)))/(v2*v2))))\n",
-      "\n",
-      "#result\n",
-      "print \"Torque angle if voltage drops to 205 V = \",alpha,\" degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Torque angle if voltage drops to 205 V =  42.9327261097  degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 38
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_1.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_1.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_2.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_2.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_3.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_3.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_4.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_4.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_5.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_5.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_6.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_6.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_7.ipynb
deleted file mode 100755
index 7e0be0a9..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter37_7.ipynb
+++ /dev/null
@@ -1,2781 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:3f52bfdb4973d016ec59d44992f6a2ce15bb8cca394c854d00d33c6af91049f3"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 37: Alternators"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.1, Page Number:1412"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "s1=36.0\n",
-      "p1=4.0\n",
-      "span1=8.0\n",
-      "s2=72.0\n",
-      "p2=6.0\n",
-      "span2=10.0\n",
-      "s3=96.0\n",
-      "p3=6.0\n",
-      "span3=12.0\n",
-      "\n",
-      "#calculations\n",
-      "alpha1=2*p1*180/s1\n",
-      "alpha2=3*p2*180/s2\n",
-      "alpha3=5*p3*180/s3\n",
-      "kc1=math.cos(math.radians(alpha1/2))\n",
-      "kc2=math.cos(math.radians(alpha2/2))\n",
-      "kc3=math.cos(math.radians(alpha3/2))\n",
-      "\n",
-      "#result\n",
-      "print \"a)kc=\",kc1\n",
-      "print \"b)kc=\",kc2\n",
-      "print \"c)kc=\",kc3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a)kc= 0.939692620786\n",
-        "b)kc= 0.923879532511\n",
-        "c)kc= 0.881921264348\n"
-       ]
-      }
-     ],
-     "prompt_number": 4
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.2, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "s=36.0\n",
-      "p=4.0\n",
-      "\n",
-      "#calculations\n",
-      "n=s/p\n",
-      "beta=180/n\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"distribution factor=\",kd"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "distribution factor= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.3, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=10.0#V\n",
-      "beta=30.0#degrees\n",
-      "m=6.0\n",
-      "\n",
-      "#calculations\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "arith_sum=6*v\n",
-      "vector_sum=kd*arith_sum\n",
-      "\n",
-      "#calculation\n",
-      "print \"emf of six coils in series=\",vector_sum,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf of six coils in series= 38.6370330516 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.4, Page Number:1414"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "beta=180/9\n",
-      "ratio=2.0/3.0\n",
-      "m1=9\n",
-      "m2=6\n",
-      "m3=3\n",
-      "\n",
-      "#calculation\n",
-      "kd1=math.sin(m1*math.radians(beta/2))/(m1*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(m2*math.radians(beta/2))/(m2*math.sin(math.radians(beta/2)))\n",
-      "kd3=math.sin(m3*math.radians(beta/2))/(m3*math.sin(math.radians(beta/2)))\n",
-      "\n",
-      "#result\n",
-      "print \"i) kd=\",kd1\n",
-      "print \"ii)kd=\",kd2\n",
-      "print \"iii)kd=\",kd3"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i) kd= 0.639863387016\n",
-        "ii)kd= 0.831206922161\n",
-        "iii)kd= 0.959795080524\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.5, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "slot=18.0\n",
-      "s=16.0\n",
-      "m1=3.0\n",
-      "m2=5.0\n",
-      "m3=7.0\n",
-      "\n",
-      "#calculations\n",
-      "span=(s-1)\n",
-      "alpha=180*3/slot\n",
-      "kc1=math.cos(math.radians(alpha/2))\n",
-      "kc3=math.cos(math.radians(m1*alpha/2))\n",
-      "kc5=math.cos(math.radians(m2*alpha/2))\n",
-      "kc7=math.cos(math.radians(m3*alpha/2))\n",
-      "\n",
-      "#result\n",
-      "print \"kc1=\",kc1\n",
-      "print \"kc3=\",kc3\n",
-      "print \"kc5=\",kc5\n",
-      "print \"kc7=\",kc7"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kc1= 0.965925826289\n",
-        "kc3= 0.707106781187\n",
-        "kc5= 0.258819045103\n",
-        "kc7= -0.258819045103\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.6, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "s=144.0\n",
-      "z=10.0\n",
-      "phi=0.03#Wb\n",
-      "n=375.0#rpm\n",
-      "\n",
-      "#calculation\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "beta=180/9\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "t=s*z/(3*2)\n",
-      "eph=4.44*1*0.96*f*phi*t\n",
-      "el=3**0.5*eph\n",
-      "#result\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"phase emf=\",eph,\"V\"\n",
-      "print \"line emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 50.0 Hz\n",
-        "phase emf= 1534.464 V\n",
-        "line emf= 2657.76961039 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 19
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.7, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=6\n",
-      "s=54\n",
-      "phi=0.1#Wb\n",
-      "n=1200#rpm\n",
-      "t=8\n",
-      "#calculations\n",
-      "beta=180/9\n",
-      "kc=math.cos(beta/2)\n",
-      "f=p*n/120\n",
-      "n=s/p\n",
-      "m=s/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=s*8/3\n",
-      "t=z/2\n",
-      "eph=4.44*0.98*0.96*f*phi*t\n",
-      "el=3**0.*eph\n",
-      "\n",
-      "#result\n",
-      "print \"eph=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "eph= 1804.529664 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 20
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.8, Page Number:1416"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=16.0\n",
-      "slots=144.0\n",
-      "z=4.0\n",
-      "n=375.0\n",
-      "airgap=5*0.01\n",
-      "theta=150.0\n",
-      "\n",
-      "#calculation\n",
-      "kf=1.11\n",
-      "alpha=(180-theta)\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "beta=180/9\n",
-      "m=slots/(p*3)\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "f=p*n/120\n",
-      "s=slots/3\n",
-      "eph=4*kf*kc*kd*f*airgap*s*4/2\n",
-      "\n",
-      "#result\n",
-      "print \"emf per phase=\",eph,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf per phase= 987.908016392 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 31
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.9, Page Number:1417"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10\n",
-      "f=50#Hz\n",
-      "n=600#rpm\n",
-      "slots=180\n",
-      "s=15\n",
-      "d=1.2#m\n",
-      "l=0.4#m\n",
-      "m=6\n",
-      "beta=180/18\n",
-      "#calculations\n",
-      "area=(1.2*3.14/p)*l\n",
-      "phi1=area*0.637\n",
-      "vr=1.1*2*f*phi1\n",
-      "vp=2**0.5*vr\n",
-      "v3=0.4*vp\n",
-      "v5=0.2*vp\n",
-      "vf=6*vp*0.966\n",
-      "vf3=6*v3*0.707\n",
-      "vf5=6*v5*0.259\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "kd2=math.sin(math.radians(3*m*beta/2))/(6*math.sin(3*math.radians(beta/2)))\n",
-      "kd3=math.sin(math.radians(5*m*beta/2))/(6*math.sin(5*math.radians(beta/2)))\n",
-      "vph=vf*2**0.5*60*kd1\n",
-      "vph3=vf3*2**0.5*60*kd2\n",
-      "vph5=vf5*2**0.5*60*kd3\n",
-      "rmsv=(vph**2+vph3**2+vph5**2)**0.5\n",
-      "rmsvl=3**0.5*(vph**2+vph5**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"i)e=\",vp,\"sin theta+\",v3,\"sin 3theta+\",v5,\"sin 5theta\"\n",
-      "print \"ii)e=\",vf,\"sin theta+\",vf3,\"sin 3theta+\",vf5,\"sin 5theta\"\n",
-      "print \"iii)rms value of phase voltage=\",rmsv,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "i)e= 14.9354392872 sin theta+ 5.97417571489 sin 3theta+ 2.98708785745 sin 5theta\n",
-        "ii)e= 86.5658061088 sin theta+ 25.3424533826 sin 3theta+ 4.64193453047 sin 5theta\n",
-        "iii)rms value of phase voltage= 7158.83679423 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 33
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.10, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=4\n",
-      "f=50.0#Hz\n",
-      "slot=60.0\n",
-      "z=4.0\n",
-      "s=3.0\n",
-      "theta=60.0\n",
-      "phi=0.943#Wb\n",
-      "\n",
-      "#calculation\n",
-      "m=slot/(p*s)\n",
-      "beta=slot/5\n",
-      "kd=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "alpha=(s/15)*180\n",
-      "kc=math.cos(math.radians(alpha/2))\n",
-      "z=slot*z/s\n",
-      "t=z/2\n",
-      "kf=1.11\n",
-      "eph=z*kf*kc*kd*f*phi*t/2\n",
-      "el=3**0.5*eph*0.1\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage= 13196.4478482 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.11, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4.0\n",
-      "f=50.0#Hz\n",
-      "slot=15.0\n",
-      "z=10.0\n",
-      "kd=0.95\n",
-      "e=1825#v\n",
-      "kc=1\n",
-      "kf=1.11\n",
-      "#calculations\n",
-      "slots=p*slot\n",
-      "slotsp=slots/3\n",
-      "turnp=20*z/2\n",
-      "phi=e/(3**0.5*p*kc*kf*kd*f*turnp)\n",
-      "z=slots*z\n",
-      "n=120*f/p\n",
-      "eg=(phi*0.001*z*n)/slots\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eg*1000,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 749.405577006 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 47
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.12, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=360#V\n",
-      "f=60.0#Hz\n",
-      "i=3.6#A\n",
-      "f2=40#Hz\n",
-      "i2=2.4#A\n",
-      "\n",
-      "#calculations\n",
-      "e2=v*i2*f2/(f*i)\n",
-      "\n",
-      "#result\n",
-      "print \"e2=\",e2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e2= 160.0 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 49
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.13, Page Number:1418"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=0\n",
-      "f=50.0#Hz\n",
-      "slot=2\n",
-      "z=4\n",
-      "theta=150#degrees\n",
-      "phi=0.12#Wb\n",
-      "per=20#%\n",
-      "\n",
-      "#calculations\n",
-      "alpha=180-theta\n",
-      "slotp=6\n",
-      "m=2\n",
-      "beta=180/slotp\n",
-      "kd1=math.sin(m*math.radians(beta/2))/(m*math.sin(math.radians(beta/2)))\n",
-      "z=10*slot*z\n",
-      "t=z/2\n",
-      "e1=4.44*kd1*kd1*f*0.12*t\n",
-      "kc3=math.cos(3*math.radians(alpha/2))\n",
-      "f2=f*3\n",
-      "phi3=(1.0/3)*per*0.12\n",
-      "e3=4.44*kd3*kd3*theta*0.008*40\n",
-      "e=(e1**2+e3**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"e=\",e,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "e= 994.25286629 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 50
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.14, Page Number:1419"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=230.0#V\n",
-      "per=10.0#%\n",
-      "per2=6.0#%\n",
-      "f=50.0#Hz\n",
-      "r=10.0#ohm\n",
-      "\n",
-      "#calculation\n",
-      "#star connection\n",
-      "e5=per*v/100\n",
-      "e=(v**2+e5**2)**0.5\n",
-      "eph=3**0.5*e\n",
-      "\n",
-      "#delta\n",
-      "e3=10*v/100\n",
-      "f3=10*3\n",
-      "i=e3/f3\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage for star=\",eph,\"V\"\n",
-      "print \"line voltage for delta=\",e3,\"V\"\n",
-      "print \"current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage for star= 400.358589267 V\n",
-        "line voltage for delta= 23.0 V\n",
-        "current= 0.766666666667 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 55
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(a), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=10.0\n",
-      "p1=24.0\n",
-      "f=25#Hz\n",
-      "p3=6.0\n",
-      "s=0.05\n",
-      "\n",
-      "#calculation\n",
-      "n=120*f/p\n",
-      "f1=p1*n/120\n",
-      "n2=120*f1/6\n",
-      "n3=(1-s)*n2\n",
-      "f2=s*f1p\n",
-      "\n",
-      "\n",
-      "#result\n",
-      "print \"frequency=\",f1,\"Hz\"\n",
-      "print \"speed=\",n3,\"rpm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency= 60.0 Hz\n",
-        "speed= 1140.0 rpm\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.15(b), Page Number:1420"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "p=4\n",
-      "phi=0.12#Wb\n",
-      "slotsp=4\n",
-      "cp=4\n",
-      "theta=150#degrees\n",
-      "\n",
-      "#calculation\n",
-      "slots=slotsp*3*p\n",
-      "c=cp*slots\n",
-      "turns=32\n",
-      "kb=math.sin(math.radians(60/2))/(p*math.sin(math.radians(7.5)))\n",
-      "kp=math.cos(math.radians(15))\n",
-      "eph=4.44*50*0.12*kb*0.966*turns\n",
-      "el=eph*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"line voltage\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line voltage 1365.94840977 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 62
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.16, Page Number:1426"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.85\n",
-      "v=11#kV\n",
-      "r=0.1#ohm\n",
-      "x=0.66#ohm\n",
-      "\n",
-      "#calculation\n",
-      "i=load*10**6/(3**0.5*v*1000*pf)\n",
-      "iradrop=i*r\n",
-      "ixsdrop=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "e0=((vp*pf+i*r)**2+(vp*sinphi+i*x)**2)**0.5\n",
-      "el=3**0.5*e0\n",
-      "\n",
-      "#result\n",
-      "print \"linevalue of emf=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "linevalue of emf= 11475.6408913 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 69
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(a), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2200.0#V\n",
-      "f=50.0#Hz\n",
-      "load=440.0#KVA\n",
-      "r=0.5#ohm\n",
-      "i=40.0#A\n",
-      "il=200.0#A\n",
-      "vf=1160.0#V\n",
-      "\n",
-      "#calculations\n",
-      "zs=vf/200\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous impedence=\",zs,\"ohm\"\n",
-      "print \"synchronous reactance=\",xs,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous impedence= 5.8 ohm\n",
-        "synchronous reactance= 5.77840808528 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 71
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.17(b), Page Number:1428"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=60.0#kVA\n",
-      "v=220.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.016#ohm\n",
-      "x=0.07#ohm\n",
-      "pf=0.7\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/v\n",
-      "ira=i*r\n",
-      "ixl=i*x\n",
-      "#unity pf\n",
-      "e=((v+ira)**2+(ixl)**2)**0.5\n",
-      "#pf of 0.7 lag\n",
-      "e2=((v*pf+ira)**2+(v*pf+ixl)**2)**0.5\n",
-      "#pf of 0.7 lead\n",
-      "e3=((v*pf+ira)**2+(v*pf-ixl)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"voltage with pf=1\",e,\"V\"\n",
-      "print \"voltage with pf=0.7 lag\",e2,\"V\"\n",
-      "print \"voltage with pf=0.7 lead\",e3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage with pf=1 225.174386048 V\n",
-        "voltage with pf=0.7 lag 234.604995966 V\n",
-        "voltage with pf=0.7 lead 208.03726621 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 75
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.18(a), Page Number:1429"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=50.0#KVA\n",
-      "v1=440.0#V\n",
-      "f=50.0#Hz\n",
-      "r=0.25#ohm\n",
-      "x=3.2#ohm\n",
-      "xl=0.5#ohm\n",
-      "\n",
-      "#calculation\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "rd=i*r\n",
-      "ixl=i*xl\n",
-      "ea=((v+rd)**2+(ixl)**2)**0.5\n",
-      "el=3**0.5*ea\n",
-      "e0=((v+rd)**2+(i*x)**2)**0.5\n",
-      "e0l=e0*3**0.5\n",
-      "per=(e0-v)/v\n",
-      "xa=x-xl\n",
-      "#result\n",
-      "print \"internal emf Ea=\",el,\"V\"\n",
-      "print \"no load emf=\",e0l,\"V\"\n",
-      "print \"percentage regulation=\",per*100,\"%\"\n",
-      "print \"valueof synchronous reactance=\",xa,\"ohm\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "internal emf Ea= 471.842539659 V\n",
-        "no load emf= 592.991130967 V\n",
-        "percentage regulation= 34.7707115833 %\n",
-        "valueof synchronous reactance= 2.7 ohm\n"
-       ]
-      }
-     ],
-     "prompt_number": 87
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.19, Page Number:1432"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "i=200.0#A\n",
-      "v=50.0#V\n",
-      "r=0.1#ohm\n",
-      "il=100.0#A\n",
-      "pf=0.8\n",
-      "vt=200.0#V\n",
-      "\n",
-      "#calculation\n",
-      "zs=v/vt\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"induced voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced voltage= 222.090276316 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 90
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.20, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=2000.0#V\n",
-      "i=100.0#A\n",
-      "pf=0.8\n",
-      "pf2=0.71\n",
-      "i2=2.5#A\n",
-      "v2=500.0#V\n",
-      "r=0.8#ohm\n",
-      "\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "sinphi2=math.sin(math.acos(pf2))\n",
-      "zs=v2/i\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "#unity pf\n",
-      "e01=((v+r*i)**2+(i*xs)**2)**0.5\n",
-      "reg1=(e01-v)*100/v\n",
-      "#at pf=0.8\n",
-      "e02=((v*pf+r*i)**2+(v*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v)*100/v\n",
-      "#at pf=0.71\n",
-      "e03=((v*pf2+r*i)**2+(v*sinphi2+i*xs)**2)**0.5\n",
-      "reg3=(e03-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation unity pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n",
-      "print \"voltage regulation 0.71 lead pf=\",reg3,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.6\n",
-        "voltage regulation unity pf= 6.88779163216 %\n",
-        "voltage regulation 0.8 lag pf= -8.875640156 %\n",
-        "voltage regulation 0.71 lead pf= 21.1141910671 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 100
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.21, Page Number:1433"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=3000.0#V\n",
-      "load=100.0#kVA\n",
-      "f=50.0#Hz\n",
-      "r=0.2\n",
-      "i1=40.0#A\n",
-      "i2=200.0#A\n",
-      "v2=1040.0#V\n",
-      "pf=0.8\n",
-      "v1=v/3**0.5\n",
-      "#calculations\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "\n",
-      "\n",
-      "#at pf=0.8 lag\n",
-      "e01=((v1*pf+r*i)**2+(v1*sinphi1+i*xs)**2)**0.5\n",
-      "reg1=(e01-v1)*100/v1\n",
-      "#at pf=0.8 lead\n",
-      "e02=((v1*pf+r*i)**2+(v1*sinphi1-i*xs)**2)**0.5\n",
-      "reg2=(e02-v1)*100/v1\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg1,\"%\"\n",
-      "print \"voltage regulation 0.8 lag pf=\",reg2,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation 0.8 lag pf= 2.20611574348 %\n",
-        "voltage regulation 0.8 lag pf= -1.77945143824 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 112
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.22, Page Number:1434"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1600.0#kVA\n",
-      "v=13500.0#V\n",
-      "r=1.5#ohm\n",
-      "x=30.0#ohm\n",
-      "load1=1280.0#kW\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi1=math.sin(math.acos(pf))\n",
-      "i=load1*1000/(3**0.5*v*pf)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi1-ixs)**2)**0.5\n",
-      "regn=(e0-vp)*100/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= -11.9909032489 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 122
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.23, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#kVA\n",
-      "v=400.0#V\n",
-      "f=50.0#Hz\n",
-      "pf=0.8\n",
-      "r=0.5#ohm\n",
-      "x=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "thetadel=math.atan((vp*sinphi+ixs)/(vp*pf+ira))\n",
-      "delta=math.degrees(thetadel)-math.degrees(math.acos(pf))\n",
-      "\n",
-      "#result\n",
-      "print \"voltage regulation=\",regn*100,\"%\"\n",
-      "print \"power angle=\",delta,\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "voltage regulation= 48.0405877623 %\n",
-        "power angle= 18.9704078085 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 127
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.24, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6000.0#KVA\n",
-      "v=6600.0#V\n",
-      "p=2.0\n",
-      "f=50.0#Hz\n",
-      "i2=125.0#A\n",
-      "v1=8000.0#V\n",
-      "i3=800.0#A\n",
-      "d=0.03\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v1/(3**0.5*i3)\n",
-      "vp=v/3**0.5\n",
-      "rd=d*vp\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=rd\n",
-      "ra=ira/il\n",
-      "xs=(zs**2-ra**2)**0.5\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+il*xs)**2)**0.5\n",
-      "reg=(e0-vp)/vp\n",
-      "\n",
-      "#result\n",
-      "print \"percentage regulation=\",reg*100,\"%\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "percentage regulation= 62.2972136768 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 133
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.25, Page Number:1435"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "load=2000#KVA\n",
-      "v=2300#V\n",
-      "i=600#A\n",
-      "v2=900#V\n",
-      "r=0.12#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "zs=v2/(3**0.5*i)\n",
-      "rp=r/2\n",
-      "re=rp*1.5\n",
-      "xs=(zs**2-re**2)**0.5\n",
-      "il=load*1000/(3**0.5*v)\n",
-      "ira=il*rp\n",
-      "ixs=il*xs\n",
-      "vp=v/3**0.5\n",
-      "e0=((vp+ira)**2+(ixs)**2)**0.5\n",
-      "reg1=(e0-vp)/vp\n",
-      "e0=((vp*pf+ira)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "reg2=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation at pf=1\",reg1*100,\"%\"\n",
-      "print \"regulation at pf=0.8\",reg2*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation at pf=1 7.32796146323 %\n",
-        "regulation at pf=0.8 23.8398862235 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 134
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.26, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=Symbol('v')\n",
-      "load=2000#KVA\n",
-      "load1=11#KV\n",
-      "r=0.3#ohm\n",
-      "x=5#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "i=load*1000/(3**0.5*load1*1000)\n",
-      "vt=load1*1000/3**0.5\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "e0=((vt*pf+ira)**2+(vt*sinphi+ixs)**2)**0.5\n",
-      "v=solve(((pf*v+ira)**2+(sinphi*v-ixs)**2)**0.5-e0,v)\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v[1],\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 6978.31767618569 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 150
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.27, Page Number:1436"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1200#KVA\n",
-      "load1=3.3#KV\n",
-      "f=50#Hz\n",
-      "r=0.25#ohm\n",
-      "i=35#A\n",
-      "i2=200#A\n",
-      "v=1.1#kV\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "zs=v*1000/(3**0.5*i2)\n",
-      "xs=(zs**2-r**2)**0.5\n",
-      "v=load1*1000/3**0.5\n",
-      "theta=math.atan(xs/r)\n",
-      "ia=load*1000/(3**0.5*load1*1000)\n",
-      "e=v+ia*zs\n",
-      "change=(e-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"per unit change=\",change"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "per unit change= 0.349909254054\n"
-       ]
-      }
-     ],
-     "prompt_number": 151
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.28, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50#Hz\n",
-      "v1=11#kV\n",
-      "load=3#MVA\n",
-      "i=100#A\n",
-      "v2=12370#V\n",
-      "vt=11000#V\n",
-      "pf=0.8\n",
-      "r=0.4#ohm\n",
-      "\n",
-      "#calculation\n",
-      "E0=v1*1000/3**0.5\n",
-      "v=v2/3**0.5\n",
-      "pf=0\n",
-      "sinphi=1\n",
-      "xs=(v-(E0**2-(i*r)**2)**0.5)/i\n",
-      "il=load*10**6/(3**0.5*v1*1000)\n",
-      "ira=il*r\n",
-      "ixs=il*xs\n",
-      "e0=((E0*pf+ira)**2+(E0*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-E0)*100/E0\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 19.6180576177 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 175
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.29, Page Number:1437"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "pf=0.8\n",
-      "vt=3500#v\n",
-      "load=2280#KW\n",
-      "v1=3300#V\n",
-      "r=8#ohm\n",
-      "x=6#ohm\n",
-      "\n",
-      "#calculation\n",
-      "vl=vt/3**0.5\n",
-      "vp=v1/3**0.5\n",
-      "il=load*1000/(3**0.5*v1*pf)\n",
-      "drop=vl-vp\n",
-      "z=(r**2+x**2)**0.5\n",
-      "x=vl/(z+drop/il)\n",
-      "vtp=vl-x*drop/il\n",
-      "vtpl=vtp*3**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",vtpl,\"V\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= 3420.781893 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 176
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.30, Page Number:1441"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3.5#MVA\n",
-      "v=4160#V\n",
-      "f=50#Hz\n",
-      "i=200#A\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "il=load*10**6/(3**0.5*v)\n",
-      "zs=4750/(3**0.5*il)\n",
-      "ra=0\n",
-      "ixs=il*zs\n",
-      "vp=v/3**0.5\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "e0=((vp*pf)**2+(vp*sinphi+ixs)**2)**0.5\n",
-      "regn=(e0-vp)/vp\n",
-      "#result\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "regulation= 0.91675794767 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 184
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.39, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "xd=0.7\n",
-      "xq=0.4\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "ia=1\n",
-      "tandelta=ia*xq*pf/(v+xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(math.radians(36.9)+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"no load voltage=\",e0,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 14.4702941001 degrees\n",
-        "no load voltage= 1.51511515874 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 185
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.40, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "f=50.0#Hz\n",
-      "xd=0.6\n",
-      "xq=0.45\n",
-      "ra=0.015\n",
-      "pf=0.8\n",
-      "ia=1\n",
-      "v=1\n",
-      "sinphi=math.sin(math.acos(pf))\n",
-      "#calculation\n",
-      "tanpsi=(v*sinphi+ia*xq)/(v*pf+ia*ra)\n",
-      "psi=math.atan(tanpsi)\n",
-      "delta=psi-math.acos(pf)\n",
-      "i_d=ia*math.sin(psi)\n",
-      "iq=ia*math.cos(psi)\n",
-      "e0=v*math.cos(delta)+iq*ra+i_d*xd\n",
-      "regn=(e0-v)*100/v\n",
-      "\n",
-      "#result\n",
-      "print \"open circuit voltage=\",e0,\"V\"\n",
-      "print \"regulation=\",regn,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "open circuit voltage= 1.44767600311 V\n",
-        "regulation= 44.7676003107 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 187
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.41, Page Number:1455"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "ia=10#A\n",
-      "phi=math.radians(20)\n",
-      "v=400#V\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "pf=math.cos(phi)\n",
-      "sinphi=math.sin(phi)\n",
-      "tandelta=ia*xq*pf/(v+ia*xq*sinphi)\n",
-      "delta=math.atan(tandelta)\n",
-      "i_d=ia*math.sin(phi+delta)\n",
-      "iq=ia*math.cos(phi+delta)\n",
-      "e0=v*math.cos(delta)+i_d*xd\n",
-      "regn=(e0-v)/v\n",
-      "\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(delta),\"degrees\"\n",
-      "print \"id=\",i_d,\"A\"\n",
-      "print \"iq=\",iq,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 8.23131209115 degrees\n",
-        "id= 4.7303232581 A\n",
-        "iq= 8.81045071911 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 189
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.42, Page Number:1459"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "e1=220#V\n",
-      "f1=60#Hz\n",
-      "e2=222#V\n",
-      "f2=59#Hz\n",
-      "\n",
-      "#calculation\n",
-      "emax=(e1+e2)/2\n",
-      "emin=(e2-e1)/2\n",
-      "f=(f1-f2)\n",
-      "epeak=emax/0.707\n",
-      "pulse=(f1-f2)*60\n",
-      "\n",
-      "#result\n",
-      "print \"max voltage=\",emax,\"V\"\n",
-      "print \"min voltage=\",emin,\"V\"\n",
-      "print \"frequency=\",f,\"Hz\"\n",
-      "print \"peak value of voltage=\",epeak,\"V\"\n",
-      "print \"number of maximum light pulsations/minute=\",pulse"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max voltage= 221 V\n",
-        "min voltage= 1 V\n",
-        "frequency= 1 Hz\n",
-        "peak value of voltage= 312.588401697 V\n",
-        "number of maximum light pulsations/minute= 60\n"
-       ]
-      }
-     ],
-     "prompt_number": 190
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.43, Page Number:1462"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "power=1500#kVA\n",
-      "v=6.6#kV\n",
-      "r=0.4#ohm\n",
-      "x=6#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "i=power*1000/(3**0.5*v*1000)\n",
-      "ira=i*r\n",
-      "ixs=i*x\n",
-      "vp=v*1000/3**0.5\n",
-      "phi=math.acos(pf)\n",
-      "tanphialpha=(vp*math.sin(phi)+ixs)/(vp*pf+ira)\n",
-      "phialpha=math.atan(tanphialpha)\n",
-      "alpha=phialpha-phi\n",
-      "\n",
-      "#result\n",
-      "print \"power angle=\",math.degrees(alpha)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power angle= 7.87684146241\n"
-       ]
-      }
-     ],
-     "prompt_number": 198
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.44, Page Number:1464"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3000#KVA\n",
-      "p=6\n",
-      "n=1000#rpm\n",
-      "v=3300#v\n",
-      "x=0.25\n",
-      "\n",
-      "#calculation\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "ixs=x*vp\n",
-      "xs=x*vp/i\n",
-      "alpha=1*p/2\n",
-      "psy=3*3.14*vp**2/(60*xs*n)\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronizing power=\",psy,\"kW\"\n",
-      "print \"torque=\",tsy*1000,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronizing power= 628.0 kW\n",
-        "torque= 5997.4 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 202
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.45, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=3#MVA\n",
-      "n=1000#rpm\n",
-      "v1=3.3#kV\n",
-      "r=0.25\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "vp=v1*1000/3**0.5\n",
-      "i=load*1000000/(3**0.5*v1*1000)\n",
-      "ixs=complex(0,r*vp)\n",
-      "xs=ixs/i\n",
-      "v=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "e0=v+ixs\n",
-      "alpha=math.atan(e0.imag/e0.real)-math.acos(pf)\n",
-      "p=6/2\n",
-      "psy=abs(e0)*vp*math.cos(alpha)*math.sin(math.radians(3))/xs\n",
-      "tsy=9.55*3*psy*100/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",-psy*3/1000,\"kW\"\n",
-      "print \"toque=\",-tsy/100,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 722.236196153j kW\n",
-        "toque= 6897.35567326j N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 221
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.46, Page Number:1465"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=750#KVA\n",
-      "v=11#kV\n",
-      "p=4\n",
-      "r=1#%\n",
-      "x=15#%\n",
-      "pf=0.8\n",
-      "#calculation\n",
-      "i=load*1000/(3**0.5*v*1000)\n",
-      "vph=v*1000/3**0.5\n",
-      "ira=r*vph/1000\n",
-      "ra=ira/i\n",
-      "xs=x*vph/(100*i)\n",
-      "zs=(ra**2+xs**2)**0.5\n",
-      "#no load\n",
-      "alpha=p/2\n",
-      "psy=math.radians(alpha)*vph**2/xs\n",
-      "#fl 0.8 pf\n",
-      "e=((vph*pf+i*ra)**2+(vph*math.sin(math.acos(pf)+i*xs))**2)**0.5\n",
-      "psy2=math.radians(alpha)*e*vph/xs\n",
-      "\n",
-      "#result\n",
-      "print \"Synchronous power at:\"\n",
-      "print \"no load=\",psy,\"W\"\n",
-      "print \"at pf of 0.8=\",psy2,\"w\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Synchronous power at:\n",
-        "no load= 58177.6417331 W\n",
-        "at pf of 0.8= 73621.2350169 w\n"
-       ]
-      }
-     ],
-     "prompt_number": 225
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.47, Page Number:1466"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=2000#KVA\n",
-      "p=8\n",
-      "n=750#rpm\n",
-      "v1=6000#V\n",
-      "pf=0.8\n",
-      "r=6#ohm\n",
-      "\n",
-      "#calculations\n",
-      "alpha=math.radians(4)\n",
-      "v=v1/3**0.5\n",
-      "i=load*1000/(3**0.5*v1)\n",
-      "e0=((v*pf)**2+(v*math.sin(math.acos(pf))+i*r)**2)**0.5\n",
-      "psy=alpha*e0*v*3/r\n",
-      "tsy=9.55*psy/n\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power=\",psy,\"W\"\n",
-      "print \"synchronous torque=\",tsy,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power= 514916.500204 W\n",
-        "synchronous torque= 6556.60343593 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 226
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.48, Page Number:1467"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "n=1500#rpm\n",
-      "f=50#Hz\n",
-      "r=20#%\n",
-      "pf=0.8\n",
-      "phi=0.5\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/3**0.5\n",
-      "i=load*1000/(3**0.5*v)\n",
-      "xs=r*vp/(1000*i)\n",
-      "p=120*f/n\n",
-      "alpha=math.radians(2)\n",
-      "#no load\n",
-      "psy=3*alpha*vp**2/(p*1000)\n",
-      "tsy=9.55*psy*1000/(n*2)\n",
-      "#pf=0.8\n",
-      "v2=vp*complex(pf,math.sin(math.acos(pf)))\n",
-      "ixs=complex(0,i*4)\n",
-      "e0=v+ixs\n",
-      "psy2=abs(e0)*vp*math.cos(math.radians(8.1))*math.sin(math.radians(2))*3/4\n",
-      "tsy2=9.55*psy2/(n*20)\n",
-      "\n",
-      "#result\n",
-      "print \"synchronous power:\"\n",
-      "print \"atno load=\",psy,\"w\"\n",
-      "print \"at 0.8 pf=\",psy2,\"w\"\n",
-      "print \"torque:\"\n",
-      "print \"at no load=\",tsy,\"N-m\"\n",
-      "print \"at pf=0.8=\",tsy2,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "synchronous power:\n",
-        "atno load= 872.664625997 w\n",
-        "at 0.8 pf= 1506057.44405 w\n",
-        "torque:\n",
-        "at no load= 2777.98239276 N-m\n",
-        "at pf=0.8= 479.428286357 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.49, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=6.6#kW\n",
-      "load1=3000#kW\n",
-      "pf=0.8\n",
-      "xa=complex(0.5,10)\n",
-      "xb=complex(0.4,12)\n",
-      "i0=150#A\n",
-      "\n",
-      "#calculation\n",
-      "v=complex(load*1000/3**0.5,0)\n",
-      "cosphi1=1500*1000/(load*1000*i0*3**0.5)\n",
-      "phi1=math.acos(cosphi1)\n",
-      "sinphi1=math.sin(phi1)\n",
-      "i=328*complex(pf,-math.sin(math.acos(pf)))\n",
-      "i1=i0*complex(cosphi1,-sinphi1)\n",
-      "i2=i-i1\n",
-      "coshi2=i2.real/181\n",
-      "ea=v+i1*xa\n",
-      "eal=3**0.5*abs(ea)\n",
-      "eb=v+i2*xb\n",
-      "ebl=3**0.5*abs(eb)\n",
-      "alpha1=(ea.imag/ea.real)\n",
-      "alpha2=(eb.imag/eb.real)\n",
-      "#result\n",
-      "print \"Ea=\",ea,\"V\"\n",
-      "print \"Eb=\",eb,\"V\"\n",
-      "print \"alpha1=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"alpha2=\",math.degrees(alpha2),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Ea= (4602.91884998+1275.81974829j) V\n",
-        "Eb= (5352.42648271+1524.56032028j) V\n",
-        "alpha1= 15.8810288383 degrees\n",
-        "alpha2= 16.3198639435 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 245
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.50, Page Number:1468"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declration\n",
-      "e1=complex(230,0)\n",
-      "e2=230*complex(0.985,0.174)\n",
-      "z1=complex(0,2)\n",
-      "z2=complex(0,3)\n",
-      "z=6\n",
-      "i1=((e1-e2)*z+e1*z2)/(z*(z1+z2)+z1*z2)\n",
-      "i2=((e2-e1)*z+e2*z1)/(z*(z1+z2)+z1*z2)\n",
-      "i=i1+i2\n",
-      "v=i*z\n",
-      "p1=abs(v)*abs(i1)*math.cos(math.atan(i1.imag/i1.real))\n",
-      "p2=abs(v)*abs(i2)*math.cos(math.atan(i2.imag/i2.real))\n",
-      "\n",
-      "#result\n",
-      "print \"terminal voltage=\",v,\"V\"\n",
-      "print \"current\",i,\"A\"\n",
-      "print \"power 1=\",p1,\"W\"\n",
-      "print \"power 2=\",p2,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "terminal voltage= (222.905384615-28.5730769231j) V\n",
-        "current (37.1508974359-4.76217948718j) A\n",
-        "power 1= 3210.60292765 W\n",
-        "power 2= 5138.29001053 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 249
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.51, Page Number:1471"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=1500#kW\n",
-      "v=11#KV\n",
-      "pf=0.867\n",
-      "x=50#ohm\n",
-      "r=4#ohm\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "il=load*1000/(3**0.5*v*1000*pf)\n",
-      "phi=math.acos(pf)\n",
-      "sinphi=math.sin(phi)\n",
-      "iwatt=il*pf\n",
-      "iwattless=il*sinphi\n",
-      "i1=il/2\n",
-      "i2=iwatt/2\n",
-      "iw1=(i**2-i1**2)**0.5\n",
-      "iw2=i2-iw1\n",
-      "ia=(i2**2+iw2**2)**0.5\n",
-      "vt=v*1000/3**0.5\n",
-      "ir=i*r\n",
-      "ix=x*i\n",
-      "cosphi=i2/i\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "e=((vt*cosphi+ir)**2+(vt*sinphi+ix)**2)**0.5\n",
-      "el=3**0.5*e\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"line voltage=\",el,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 43.4628778514 A\n",
-        "line voltage= 14304.0798593 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.52, Page Number:1472"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10#MW\n",
-      "pf=0.8\n",
-      "output=6000#kW\n",
-      "pfa=0.92\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "phia=math.acos(pfa)\n",
-      "tanphi=math.tan(phi)\n",
-      "tanphia=math.tan(phia)\n",
-      "loadkvar=load*1000*tanphi\n",
-      "akvar=output*tanphia\n",
-      "kwb=(load*1000-output)\n",
-      "kvarb=loadkvar-akvar\n",
-      "kvab=complex(kwb,kvarb)\n",
-      "pfb=math.cos(math.atan(kvab.imag/kvab.real))\n",
-      "kvarb=kwb*pfb\n",
-      "kvara=-loadkvar-kvarb\n",
-      "kvaa=complex(output,kvara)\n",
-      "pfa=math.cos(math.atan(kvaa.imag/kvaa.real))\n",
-      "\n",
-      "#result\n",
-      "print \"new pfb=\",pfb\n",
-      "print \"new pfa=\",pfa"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new pfb= 0.628980253433\n",
-        "new pfa= 0.513894032194\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.54, Page Number:1473"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "load=1000#KVA\n",
-      "x=20#%\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculation\n",
-      "i=87.5\n",
-      "x=8.7\n",
-      "vp=3810\n",
-      "e0=4311\n",
-      "ir=70\n",
-      "ix=52.5\n",
-      "IX=762\n",
-      "vb1=(e0**2-vp**2)**0.5\n",
-      "i1x=vb1\n",
-      "i1=i1x/x\n",
-      "output=3**0.5*v*i1/1000\n",
-      "b2v=(vp**2+e0**2)**0.5\n",
-      "i2z=b2v\n",
-      "i2=b2v/x\n",
-      "i2rx=e0\n",
-      "i2r=i2rx/x\n",
-      "i2x=vp/x\n",
-      "tanphi2=i2x/i2r\n",
-      "phi2=math.atan(tanphi2)\n",
-      "cosphi2=math.cos(phi2)\n",
-      "output1=3**0.5*v*i2*cosphi2/1000\n",
-      "\n",
-      "#result\n",
-      "print \"power output at unity pf=\",output,\"kW\"\n",
-      "print \"max power output=\",output1,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " power output at unity pf= 2650.38477722 kW\n",
-        "max power output= 5664.52285143 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 255
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.55, Page Number:1474"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "x=10.0#ohm\n",
-      "i=220.0#A\n",
-      "load=11.0#kV\n",
-      "per=25.0#%\n",
-      "\n",
-      "#calculations\n",
-      "oa1=load*1000/3**0.5\n",
-      "a1c1=i*x\n",
-      "e0=(oa1**2+a1c1**2)**0.5\n",
-      "emf=(1+per/100)*e0\n",
-      "a1a2=(emf**2-a1c1**2)**0.5-oa1\n",
-      "ix=a1a2/x\n",
-      "i1=(i**2+ix**2)**0.5\n",
-      "pf=i/i1\n",
-      "bv=(oa1**2+emf**2)**0.5\n",
-      "imax=bv/x\n",
-      "ir=emf/x\n",
-      "ix=oa1/x\n",
-      "pfmax=ir/imax\n",
-      "output=3**0.5*load*1000*imax*pfmax*0.001\n",
-      "#result\n",
-      "print \"new current=\",i1,\"A\"\n",
-      "print \"new power factor=\",pf\n",
-      "print \"max power output=\",output,\"kW\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new current= 281.573453399 A\n",
-        "new power factor= 0.781323655849\n",
-        "max power output= 16006.7954319 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 258
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.56, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=20.0#MVA\n",
-      "load1=35.0#MVA\n",
-      "pf=0.8\n",
-      "output=25.0#MVA\n",
-      "cosphi1=0.9\n",
-      "\n",
-      "#calculations\n",
-      "loadmw=load1*pf\n",
-      "loadmvar=load1*0.6\n",
-      "sinphi=math.sin(math.acos(cosphi))\n",
-      "mva1=25\n",
-      "mw1=mva1*cosphi1\n",
-      "mvar1=25*sinphi1\n",
-      "mw2=loadmw-mw1\n",
-      "mvar2=loadmvar-mvar1\n",
-      "mva2=(mw2**2+mvar2**2)**0.5\n",
-      "cosphi2=mw2/mva2\n",
-      "\n",
-      "#result\n",
-      "print \"output=\",mva2\n",
-      "print \"pf=\",cosphi2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "output= 10.4509862952\n",
-        "pf= 0.52626611926\n"
-       ]
-      }
-     ],
-     "prompt_number": 260
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.57, Page Number:1475"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declarations\n",
-      "load=600#KW\n",
-      "loadm=707#kW\n",
-      "pf=0.707\n",
-      "output=900#kW\n",
-      "pf1=0.9\n",
-      "\n",
-      "#calculation\n",
-      "kva=1000\n",
-      "kvar=kva*(1-pf1**2)**0.5\n",
-      "active_p=1307-output\n",
-      "reactive_p=loadm-kvar\n",
-      "\n",
-      "#result\n",
-      "print \"active power shared by second machine=\",active_p,\"kW\"\n",
-      "print \"reactive power shared by second machine=\",reactive_p,\"kVAR\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "active power shared by second machine= 407 kW\n",
-        "reactive power shared by second machine= 271.110105646 kVAR\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.58, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "l1=500#kW\n",
-      "l2=1000#kW\n",
-      "pf1=0.9\n",
-      "l3=800#kW\n",
-      "pf2=0.8\n",
-      "l4=500#kW\n",
-      "pf3=0.9\n",
-      "output=1500#kW\n",
-      "pf=0.95\n",
-      "\n",
-      "#calculation\n",
-      "kw1=l1\n",
-      "kw2=l2\n",
-      "kw3=l3\n",
-      "kw4=500\n",
-      "kvar2=kw2*0.436/pf1\n",
-      "kvar3=kw3*0.6/pf2\n",
-      "kvar4=kw4*0.436/pf3\n",
-      "kvar=output/pf\n",
-      "kw=kw1+kw2+kw3+kw4-output\n",
-      "kvar=kvar2+kvar3+kvar4-kvar\n",
-      "cosphi=math.cos(math.atan(kvar/kw))\n",
-      "\n",
-      "#result\n",
-      "print \"kW output=\",kw\n",
-      "print \"pf=\",cosphi"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kW output= 1300\n",
-        "pf= 0.981685651341\n"
-       ]
-      }
-     ],
-     "prompt_number": 264
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.59, Page Number:1476"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "z=complex(0.2,2)\n",
-      "ze=complex(3,4)\n",
-      "emf1=complex(2000,0)\n",
-      "emf2=complex(22000,100)\n",
-      "\n",
-      "#calculations\n",
-      "i1=complex(68.2,-102.5)\n",
-      "i2=complex(127,-196.4)\n",
-      "i=i1+i2\n",
-      "v=i*ze\n",
-      "pva1=v*i1\n",
-      "kw1=pva1.real*3\n",
-      "a11=math.atan(-i1.imag/i1.real)\n",
-      "a12=math.atan(-v.imag/v.real)\n",
-      "pf1=math.cos(a11-a12)\n",
-      "pva2=v*i2\n",
-      "kw2=pva2.real*3\n",
-      "a21=math.atan(-i2.imag/i2.real)\n",
-      "a22=math.atan(-v.imag/v.real)\n",
-      "pf2=math.cos(a21-a22)\n",
-      "\n",
-      "#result\n",
-      "print \"kw output 1=\",kw1/1000\n",
-      "print \"pf 1=\",pf1\n",
-      "print \"kw output 2=\",kw2/1000\n",
-      "print \"pf 2=\",pf2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "kw output 1= 328.79427\n",
-        "pf 1= 0.606839673468\n",
-        "kw output 2= 610.34892\n",
-        "pf 2= 0.596381892841\n"
-       ]
-      }
-     ],
-     "prompt_number": 273
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.63, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=5000#KVA\n",
-      "v=10000#V\n",
-      "f=50#Hz\n",
-      "ns=1500#rpm\n",
-      "j=1.5*10**4#khm2\n",
-      "ratio=5\n",
-      "\n",
-      "#calculation\n",
-      "t=0.0083*ns*(j/(load*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"natural time period of oscillation=\",round(t,3),\"s\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "natural time period of oscillation= 1.364 s\n"
-       ]
-      }
-     ],
-     "prompt_number": 275
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.64, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10000#KVA\n",
-      "p=4\n",
-      "v=6600#V\n",
-      "f=50#Hz\n",
-      "xs=25#%\n",
-      "pf=1.5\n",
-      "\n",
-      "#calculations\n",
-      "ratio=100/xs\n",
-      "ns=120*f/p\n",
-      "j=(pf/(0.0083*ns))**2*load*ratio*f\n",
-      "\n",
-      "#result\n",
-      "print \"moment of inertia=\",j/1000,\"x10^4 kg-m2\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "moment of inertia= 29.0317898098 x10^4 kg-m2\n"
-       ]
-      }
-     ],
-     "prompt_number": 277
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.65, Page Number:1481"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=10.0#MVA\n",
-      "v=10.0#kV\n",
-      "f=50.0#Hz\n",
-      "ns=1500.0#rpm\n",
-      "j=2.0*10**5#kgm2\n",
-      "x=40.0\n",
-      "\n",
-      "#calculation\n",
-      "ratio=100.0/x\n",
-      "t=0.0083*ns*(j/(load*1000*ratio*f))**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"frequency of oscillation of the rotor=\",round(1/t,1),\"Hz\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "frequency of oscillation of the rotor= 0.2 Hz\n"
-       ]
-      }
-     ],
-     "prompt_number": 283
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.66, Page Number:1483"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "v=11#kV\n",
-      "z=complex(1,10)\n",
-      "emf=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "e=emf*1000/3**0.5\n",
-      "v=v*1000/3**0.5\n",
-      "costheta=z.real/abs(z)\n",
-      "pmax=e*v*3/(z.imag*1000)\n",
-      "pmax_per_phase=(v/abs(z))*(e-(v/abs(z)))*3\n",
-      "\n",
-      "#result\n",
-      "print \"max output =\",pmax_per_phase/1000,\"kW\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "max output = 14125.5529273 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 285
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 37.67, Page Number:1484"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "load=11#kVA\n",
-      "load1=10#MW\n",
-      "z=complex(0.8,8.0)\n",
-      "v=14#kV\n",
-      "\n",
-      "#calculations\n",
-      "pmax=(load*1000/3**0.5)*(v*1000/3**0.5)*3/z.imag\n",
-      "imax=((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5/z.imag\n",
-      "pf=(v/3**0.5)*1000/((v*1000/3**0.5)**2+(load*1000/3**0.5)**2)**0.5\n",
-      "\n",
-      "#result\n",
-      "print \"maximum output=\",pmax/1000000,\"MW\"\n",
-      "print \"current=\",imax,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum output= 19.25 MW\n",
-        "current= 1284.92866209 A\n",
-        "pf= 0.786318338822\n"
-       ]
-      }
-     ],
-     "prompt_number": 289
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_1.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_1.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_2.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_2.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_3.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_3.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_4.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_4.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_5.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_5.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_6.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_6.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_7.ipynb
deleted file mode 100755
index eb91f537..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter38_7.ipynb
+++ /dev/null
@@ -1,1682 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:a6bbecd88376ba06b11df7bbad39447a579ab954844d7c4715263117b7255967"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 38: Synchronous Motor"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.1, Page Number:1495"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "p=75#kW\n",
-      "f=50#Hz\n",
-      "v=440#V\n",
-      "pf=0.8\n",
-      "loss=0.95\n",
-      "xs=2.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "ns=120*f/4\n",
-      "pm=p*1000/loss\n",
-      "ia=pm/(math.sqrt(3)*v*pf)\n",
-      "vol_phase=v/math.sqrt(3)\n",
-      "\n",
-      "#calculations\n",
-      "print \"mechanical power=\",pm,\"W\"\n",
-      "print \"armature current=\",ia,\"A\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "mechanical power= 78947.3684211 W\n",
-        "armature current= 129.489444346 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.2, Page Number:1498"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import cmath\n",
-      "#variable declaration\n",
-      "p=20\n",
-      "vl=693#V\n",
-      "r=10#ohm\n",
-      "lag=0.5#degrees\n",
-      "\n",
-      "#calculations\n",
-      "#lag=0.5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "print \"displacement:0.5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\"\n",
-      "print \"\"\n",
-      "\n",
-      "#lag=5\n",
-      "lag=5\n",
-      "alpha=p*lag/2\n",
-      "eb=vp=vl/math.sqrt(3)\n",
-      "er=complex(vp-eb*math.cos(math.radians(alpha)),eb*math.sin(math.radians(alpha)))\n",
-      "zs=complex(0,10)\n",
-      "ia=er/zs\n",
-      "power_input=3*vp*abs(ia)*math.cos(math.radians(cmath.phase(ia)))\n",
-      "\n",
-      "print \"displacement:5%\"\n",
-      "print \"alpha=\",alpha,\"degrees\"\n",
-      "print \"armature emf/phase=\",eb,\"V\"\n",
-      "print \"armature current/phase=\",ia,\"A\"\n",
-      "print \"power drawn=\",power_input,\"W\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "displacement:0.5%\n",
-        "alpha= 5.0 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (3.4871338335-0.152251551219j) A\n",
-        "power drawn= 4189.63221768 W\n",
-        "\n",
-        "displacement:5%\n",
-        "alpha= 50 degrees\n",
-        "armature emf/phase= 400.103736548 V\n",
-        "armature current/phase= (30.6497244054-14.2922012106j) A\n",
-        "power drawn= 40591.222447 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 13
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.3, Page Number:1499"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400.0#V/ph\n",
-      "i=32.0#A/ph\n",
-      "xs=10.0#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xs)**2)\n",
-      "delta=math.atan((i*xs)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n",
-      "\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 512.249938995 V\n",
-        "delta= 38.6598082541 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 15
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.4, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "w=150#kW\n",
-      "f=50#Hz\n",
-      "v=2300#V\n",
-      "n=1000#rpm\n",
-      "xd=32#ohm\n",
-      "xq=20#ohm\n",
-      "alpha=16#degrees\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=2*vp\n",
-      "ex_power=eb*vp*math.sin(math.radians(alpha))/xd\n",
-      "rel_power=(vp**2*(xd-xq)*math.sin(math.radians(2*alpha)))/(2*xd*xq)\n",
-      "pm=3*(ex_power+rel_power)\n",
-      "tg=9.55*pm/1000\n",
-      "\n",
-      "#result\n",
-      "print \"torque=\",tg,\"N-m\"\n",
-      "\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "torque= 1121.29686485 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 27
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.6, Page Number:1506"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=11000#V\n",
-      "ia=60#A\n",
-      "r=1#ohm\n",
-      "x=30#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "p2=math.sqrt(3)*v*ia*pf\n",
-      "cu_loss=ia**2*3\n",
-      "pm=p2-cu_loss\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=x\n",
-      "z_drop=ia*zs\n",
-      "eb=math.sqrt((vp**2+z_drop**2-(2*vp*z_drop*math.cos(theta+phi))))*math.sqrt(3)\n",
-      "\n",
-      "#result\n",
-      "print \"power supplied=\",p2/1000,\"kW\"\n",
-      "print \"mechanical power=\",pm/1000,\"KW\"\n",
-      "print \"induced emf=\",eb,\"V\"\n",
-      "\n",
-      "    "
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power supplied= 914.522826396 kW\n",
-        "mechanical power= 903.722826396 KW\n",
-        "induced emf= 13039.2734763 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 1
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.7, Page Number:1507"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "i=32#A\n",
-      "pf=1\n",
-      "xd=10#ohm\n",
-      "xq=6.5#ohm\n",
-      "\n",
-      "#calculations\n",
-      "e=math.sqrt(v**2+(i*xq)**2)+((xd-xq)*14.8)\n",
-      "delta=math.atan((i*xq)/v)\n",
-      "power=3*v*i\n",
-      "power_other=3*(v*e/10)*math.sin(delta)*0.001\n",
-      "\n",
-      "#result\n",
-      "print \"E=\",e,\"V\"\n",
-      "print \"delta=\",math.degrees(delta),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "E= 502.648089715 V\n",
-        "delta= 27.4744316263 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 60
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.8, Page Number:1508"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=500#V\n",
-      "output=7.46#kW\n",
-      "pf=0.9\n",
-      "r=0.8#ohm\n",
-      "loss=500#W\n",
-      "ex_loss=800#W\n",
-      "\n",
-      "#calculations\n",
-      "pm=output*1000+loss+ex_loss\n",
-      "ia=(v*pf-math.sqrt(v**2*pf**2-4*r*pm))/(2*r)\n",
-      "m_input=loss*ia*pf\n",
-      "efficiency=output*1000/m_input\n",
-      "\n",
-      "#result\n",
-      "print \"commercial efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "commercial efficiency= 82.1029269497 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 3
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.9, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2300#V\n",
-      "r=0.2#ohm\n",
-      "x=2.2#ohm\n",
-      "pf=0.5\n",
-      "il=200#A\n",
-      "\n",
-      "#calculations\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x//r)\n",
-      "v=v/math.sqrt(3)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))\n",
-      "\n",
-      "#result\n",
-      "print \"Eb=\",eb,\"volt/phase\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Eb= 1708.04482042 volt/phase\n"
-       ]
-      }
-     ],
-     "prompt_number": 12
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.10, Page Number:1509"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "vl=6600#V\n",
-      "f=50#Hz\n",
-      "il=50#A\n",
-      "r=1#ohm\n",
-      "x=20#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "#0.8 lagging\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi-theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 lag: Eb=\",eb\n",
-      "\n",
-      "#0.8 leading\n",
-      "power_i=math.sqrt(3)*v*f*pf\n",
-      "v=vl/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(x/r)\n",
-      "zs=math.sqrt(x**2+r**2)\n",
-      "eb=math.sqrt(v**2+(il*zs)**2-(2*v*il*zs*math.cos(phi+theta)))*math.sqrt(3)\n",
-      "\n",
-      "print \"0.8 leading:Eb=\",eb"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "0.8 lag: Eb= 5651.1180113\n",
-        "0.8 leading:Eb= 7705.24623679\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.11, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "x=0.4\n",
-      "pf=0.8\n",
-      "v=100#V\n",
-      "phi=math.acos(pf)\n",
-      "#calculations\n",
-      "#pf=1\n",
-      "eb=math.sqrt(v**2+(x*v)**2)\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)-phi)))\n",
-      "#pf=0.8 lead\n",
-      "eb3=math.sqrt(v**2+(x*v)**2-(2*v*x*v*math.cos(math.radians(90)+phi)))\n",
-      "#result\n",
-      "print \"pf=1: Eb=\",eb,\"V\"\n",
-      "print \"pf=0.8 lag:Eb=\",eb2,\"V\"\n",
-      "print \"pf=0.8 lead:Eb=\",eb3,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf=1: Eb= 107.703296143 V\n",
-        "pf=0.8 lag:Eb= 82.4621125124 V\n",
-        "pf=0.8 lead:Eb= 128.062484749 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 25
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.12, Page Number:1510"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaraion\n",
-      "load=1000#kVA\n",
-      "v=11000#V\n",
-      "r=3.5#ohm\n",
-      "x=40#ohm\n",
-      "pf=0.8\n",
-      "\n",
-      "#calculations\n",
-      "ia=load*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "phi=math.acos(pf)\n",
-      "ra=ia*r\n",
-      "xa=ia*x\n",
-      "za=math.sqrt(ra**2+xa**2)\n",
-      "theta=math.atan(x/r)\n",
-      "\n",
-      "#pf=1\n",
-      "eb1=math.sqrt(vp**2+za**2-(2*vp*za*math.cos(theta)))\n",
-      "alpha1=math.asin(xa*math.sin(theta)/eb1)\n",
-      "\n",
-      "#pf=0.8 lag\n",
-      "eb2=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta-phi)))*math.sqrt(3)\n",
-      "alpha2=math.asin(xa*math.sin(theta-phi)/eb2)\n",
-      "#pf=1\n",
-      "eb3=math.sqrt(vp**2+xa**2-(2*vp*xa*math.cos(theta+phi)))*math.sqrt(3)\n",
-      "alpha3=math.asin(xa*math.sin(theta+phi)/eb3)\n",
-      "\n",
-      "#result\n",
-      "print \"at pf=1\"\n",
-      "print \"Eb=\",eb1*math.sqrt(3),\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha1),\"degrees\"\n",
-      "print \"at pf=0.8 lagging\"\n",
-      "print \"Eb=\",eb2,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"at pf=0.8 leading\"\n",
-      "print \"Eb=\",eb3,\"V\"\n",
-      "print \"alpha=\",math.degrees(alpha3),\"degrees\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "at pf=1\n",
-        "Eb= 11283.8105339 V\n",
-        "alpha= 18.7256601694 degrees\n",
-        "at pf=0.8 lagging\n",
-        "Eb= 8990.39249633 V\n",
-        "alpha= 10.0142654731 degrees\n",
-        "at pf=0.8 leading\n",
-        "Eb= 13283.8907748 V\n",
-        "alpha= 7.71356041367 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 56
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.14, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=complex(0.5,0.866)\n",
-      "v=200#V\n",
-      "output=6000#W\n",
-      "loss=500#W\n",
-      "i=50#A\n",
-      "\n",
-      "#calculations\n",
-      "cu_loss=i**2*z.real\n",
-      "motor_intake=output+loss+cu_loss\n",
-      "phi=math.acos(motor_intake/(v*i))\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "zs=abs(z)*i\n",
-      "eb1=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)-phi)))\n",
-      "eb2=math.sqrt(v**2+zs**2-(2*v*zs*math.cos(math.radians(60)+phi)))\n",
-      "#result\n",
-      "print \"lag:eb=\",eb1,\"V\"\n",
-      "print \"lag:eb=\",eb2,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "lag:eb= 154.286783862 V\n",
-        "lag:eb= 213.765547573 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 65
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.15, Page Number:1513"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=2200#V\n",
-      "f=50#Hz\n",
-      "z=complex(0.4,6)\n",
-      "lag=3#degrees\n",
-      "\n",
-      "#calculations\n",
-      "eb=v/math.sqrt(3)\n",
-      "alpha=lag*8/2\n",
-      "er=math.sqrt(eb**2+eb**2-(2*eb*eb*(math.cos(math.radians(alpha)))))\n",
-      "zs=abs(z)\n",
-      "ia=er/zs\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=theta-(math.asin(eb*math.sin(math.radians(alpha))/er))\n",
-      "pf=math.cos(phi)\n",
-      "total_input=3*eb*ia*pf\n",
-      "cu_loss=3*ia**2*z.real\n",
-      "pm=total_input-cu_loss\n",
-      "pm_max=(eb*eb/zs)-(eb**2*z.real/(zs**2))\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"power of the motor=\",pm/1000,\"kW\"\n",
-      "print \"max power of motor=\",pm_max/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 44.1583059199 A\n",
-        "power factor= 0.99927231631\n",
-        "power of the motor= 165.803353329 kW\n",
-        "max power of motor= 250.446734776 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 72
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.16, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "eb=250#V\n",
-      "lead=150#degrees\n",
-      "v=200#V\n",
-      "x=2.5#times resistance\n",
-      "alpha=lead/3\n",
-      "#calculations\n",
-      "er=math.sqrt(v**2+eb**2-(2*v*eb*math.cos(math.radians(alpha))))\n",
-      "theta=math.atan(x)\n",
-      "phi=math.radians(90)-theta\n",
-      "pf=math.cos(phi)\n",
-      "\n",
-      "#results\n",
-      "print \"pf at which the motor is operating=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "pf at which the motor is operating= 0.928476690885\n"
-       ]
-      }
-     ],
-     "prompt_number": 73
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.17, Page Number:1514"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "r=10#ohm\n",
-      "inpt=900#kW\n",
-      "e=8900#V\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "icos=inpt*1000/(math.sqrt(3)*v)\n",
-      "bc=r*icos\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi=math.atan(oc/bc)\n",
-      "i=icos/math.cos(phi)\n",
-      "\n",
-      "#result\n",
-      "print \"Line current=\",i,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Line current= 149.188331836 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 82
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.18, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=6600#V\n",
-      "x=20#ohm\n",
-      "inpt=1000#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500#kW\n",
-      "\n",
-      "#variable declaration\n",
-      "va=v/math.sqrt(3)\n",
-      "ia1=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "zs=x\n",
-      "phi=math.acos(pf)\n",
-      "ia1zs=ia1*zs\n",
-      "eb=math.sqrt(va**2+ia1zs**2-(2*va*ia1zs*math.cos(math.radians(90)+phi)))\n",
-      "ia2cosphi2=inpt2*1000/(math.sqrt(3)*v)\n",
-      "cosphi2=x*ia2cosphi2\n",
-      "ac=math.sqrt(eb**2-cosphi2*2)\n",
-      "phi2=math.atan(ac/cosphi2)\n",
-      "pf=math.cos(phi2)\n",
-      "alpha2=math.atan(cosphi2/ac)\n",
-      "\n",
-      "#results\n",
-      "print \"new power angle=\",math.degrees(alpha2),\"degrees\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power angle= 25.8661450552 degrees\n",
-        "new power factor= 0.436270181217\n"
-       ]
-      }
-     ],
-     "prompt_number": 97
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.19, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=5472#W\n",
-      "x=10#ohm\n",
-      "\n",
-      "#calculations\n",
-      "va=v/math.sqrt(3)\n",
-      "iacosphi=inpt/(math.sqrt(3)*v)\n",
-      "zs=x\n",
-      "iazs=iacosphi*zs\n",
-      "ac=math.sqrt(va**2-iazs**2)\n",
-      "oc=va-ac\n",
-      "bc=iazs\n",
-      "phi=math.atan(oc/iazs)\n",
-      "pf=math.cos(phi)\n",
-      "ia=iacosphi/pf\n",
-      "alpha=math.atan(bc/ac)\n",
-      "#result\n",
-      "print \"load angle=\",math.degrees(alpha),\"degrees\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"armature current=\",ia,\"A\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "load angle= 19.9987718079 degrees\n",
-        "power factor= 0.984809614116\n",
-        "armature current= 8.01997824686 A\n"
-       ]
-      }
-     ],
-     "prompt_number": 2
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.20, Page Number:1515"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "i2=Symbol('i2')\n",
-      "v=2000.0#V\n",
-      "r=0.2#ohm\n",
-      "xs=2.2#ohm\n",
-      "inpt=800.0#kW\n",
-      "e=2500.0#V\n",
-      "\n",
-      "#calculations\n",
-      "i1=inpt*1000/(math.sqrt(3)*v)\n",
-      "vp=v/math.sqrt(3)\n",
-      "ep=e/math.sqrt(3)\n",
-      "theta=math.atan(xs/r)\n",
-      "i2=solve(((i1*xs+r*i2)**2+(vp+i1*r-xs*i2)**2)-ep**2,i2)\n",
-      "i=math.sqrt(i1**2+i2[0]**2)\n",
-      "pf=i1/i\n",
-      "\n",
-      "#result\n",
-      "print \"line currrent=\",i,\"A\"\n",
-      "print \"power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "line currrent= 241.492937915 A\n",
-        "power factor= 0.956301702525\n"
-       ]
-      }
-     ],
-     "prompt_number": 152
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.21, Page Number:1516"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=440#V\n",
-      "f=50#Hz\n",
-      "inpt=7.46#kW\n",
-      "r=0.5#ohm\n",
-      "pf=0.75\n",
-      "loss=500#W\n",
-      "ex_loss=650#W\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "cu_loss=3*ia**2*r\n",
-      "power=inpt*1000+ex_loss\n",
-      "output=inpt*1000-cu_loss-loss\n",
-      "efficiency=output/power\n",
-      "\n",
-      "#result\n",
-      "print \"armature current=\",ia,\"A\"\n",
-      "print \"power=\",power,\"W\"\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "armature current= 13.0516151762 A\n",
-        "power= 8110.0 W\n",
-        "efficiency= 82.6693343026 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 156
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.22, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "v=3300#V\n",
-      "x=18#ohm\n",
-      "pf=0.707\n",
-      "inpt=800#kW\n",
-      "\n",
-      "#calculations\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "ip=ia/math.sqrt(3)\n",
-      "zs=x\n",
-      "iazs=ip*zs\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.radians(90)\n",
-      "eb=math.sqrt(v**2+iazs**2-(2*v*iazs*(-1)*pf))\n",
-      "alpha=math.asin(iazs*math.sin(theta+phi)/eb)\n",
-      "\n",
-      "#result\n",
-      "print \"excitation emf=\",eb,\"V\"\n",
-      "print \"rotor angle=\",math.degrees(alpha),\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 4972.19098879 V\n",
-        "rotor angle= 17.0098509277 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 157
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.23, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=75#kW\n",
-      "v=400#V\n",
-      "r=0.04#ohm\n",
-      "x=0.4#ohm\n",
-      "pf=0.8\n",
-      "efficiency=0.925\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "ia=input_m/(math.sqrt(3)*v)\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "iazs=ia*zs\n",
-      "phi=math.atan(x/r)\n",
-      "theta=math.radians(90)-phi\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "cu_loss=3*ia**2*r\n",
-      "ns=120*50/40\n",
-      "pm=input_m-cu_loss\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"emf=\",eb,\"eb\"\n",
-      "print \"mechanical power=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "emf= 235.683320812 eb\n",
-        "mechanical power= 79437.5456538 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 158
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.24, Page Number:1517"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "r=0.5#ohm\n",
-      "zs=x=4#ohm\n",
-      "i=15#A\n",
-      "i2=60#A\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "iazs=i*zs\n",
-      "xs=math.sqrt(x**2-r**2)\n",
-      "theta=math.atan(xs/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta)))\n",
-      "iazs2=i2*zs\n",
-      "phi=theta-math.acos(vp**2-vp**2+iazs2**2/(2*vp*iazs2))\n",
-      "pf=math.cos(phi)\n",
-      "input_m=math.sqrt(3)*v*i2*pf\n",
-      "cu_loss=3*i2**2*r\n",
-      "pm=input_m-cu_loss\n",
-      "ns=120*50/6\n",
-      "tg=9.55*pm/ns\n",
-      "\n",
-      "#result\n",
-      "print \"gross torque developed=\",tg,\"N-m\"\n",
-      "print \"new power factor=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "gross torque developed= 310.739709828 N-m\n",
-        "new power factor= 0.912650996943\n"
-       ]
-      }
-     ],
-     "prompt_number": 161
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.25, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=7.46#kW\n",
-      "xs=10#W/phase\n",
-      "efficiency=0.85\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt*1000/efficiency\n",
-      "il=input_m/(math.sqrt(3)*v)\n",
-      "zs=il*xs\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=math.sqrt(vp**2+zs**2)\n",
-      "\n",
-      "#result\n",
-      "print \"minimum current=\",il,\"A\"\n",
-      "print \"inducedemf=\",eb,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "minimum current= 12.6677441416 A\n",
-        "inducedemf= 263.401798584 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 164
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.26, Page Number:1518"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "f=50#Hz\n",
-      "inpt=37.5#kW\n",
-      "efficiency=0.88\n",
-      "zs=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "input_m=inpt/efficiency\n",
-      "ia=input_m*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "er=ia*abs(zs)\n",
-      "phi=math.acos(pf)\n",
-      "theta=math.atan(zs.imag/zs.real)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(math.sin(theta+phi)*er/eb)\n",
-      "pm=3*eb*vp*math.sin(alpha)/abs(zs)\n",
-      "#result\n",
-      "print \"excitation emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power developed=\",pm,\"W\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "excitation emf= 495.407915636 V\n",
-        "total mechanical power developed= 44844.4875189 W\n"
-       ]
-      }
-     ],
-     "prompt_number": 206
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.27, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "import scipy\n",
-      "from sympy.solvers import solve\n",
-      "from sympy import Symbol\n",
-      "#variable declaration\n",
-      "v=6600.0#V\n",
-      "xs=20.0#ohm\n",
-      "inpt=1000.0#kW\n",
-      "pf=0.8\n",
-      "inpt2=1500.0#kW\n",
-      "phi2=Symbol('phi2')\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "ia=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "theta=math.radians(90)\n",
-      "er=ia*xs\n",
-      "zs=xs\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+er**2-(2*vp*er*math.cos(theta+phi)))\n",
-      "alpha=math.asin(inpt2*1000*zs/(3*eb*vp))\n",
-      "#vp/eb=cos(alpha+phi2)/cos(phi2)\n",
-      "#solving we get\n",
-      "phi2=math.radians(19.39)\n",
-      "pf=math.cos(phi2)\n",
-      "#result\n",
-      "print \"new power factor=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "new power factor= 0.943280616635\n"
-       ]
-      }
-     ],
-     "prompt_number": 228
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.28, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "x=4#ohms/phase\n",
-      "r=0.5#ohms/phase\n",
-      "ia=60#A\n",
-      "pf=0.866\n",
-      "loss=2#kW\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(complex(r,x))\n",
-      "phi=math.acos(pf)\n",
-      "iazs=ia*zs\n",
-      "theta=math.atan(x/r)\n",
-      "eb=math.sqrt(vp**2+iazs**2-(2*vp*iazs*math.cos(theta+phi)))\n",
-      "pm_max=(eb*vp/zs)-(eb**2*r/zs**2)\n",
-      "pm=3*pm_max\n",
-      "output=pm-loss*1000\n",
-      "\n",
-      "#result\n",
-      "print \"maximum power output=\",output/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum power output= 51.3898913442 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 229
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.29, Page Number:1519"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "z=10#ohm\n",
-      "x=0.5#ohm\n",
-      "v=2000#V\n",
-      "f=25#Hz\n",
-      "eb=1600#V\n",
-      "\n",
-      "#calculations\n",
-      "pf=x/z\n",
-      "pm_max=(eb*v/z)-(eb**2*pf/zs)\n",
-      "ns=120*f/6\n",
-      "tg_max=9.55*pm_max/ns\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total torque=\",tg_max,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total torque= 5505.51976175 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 231
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.30, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variabke declaration\n",
-      "v=2000#V\n",
-      "n=1500#rpm\n",
-      "x=3#ohm/phase\n",
-      "ia=200#A\n",
-      "\n",
-      "#calculations\n",
-      "eb=vp=v/math.sqrt(3)\n",
-      "zs=ia*x\n",
-      "sinphi=(eb**2-vp**2-zs**2)/(2*zs*vp)\n",
-      "phi=math.asin(sinphi)\n",
-      "pf=math.cos(phi)\n",
-      "pi=math.sqrt(3)*v*ia*pf/1000\n",
-      "tg=9.55*pi*1000/n\n",
-      "\n",
-      "#result\n",
-      "print \"power input=\",pi,\"kW\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"torque=\",tg,\"N-m\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power input= 669.029147347 kW\n",
-        "power factor= 0.965660395791\n",
-        "torque= 4259.48557144 N-m\n"
-       ]
-      }
-     ],
-     "prompt_number": 234
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.31, Page Number:1520"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=3300#V\n",
-      "r=2#ohm\n",
-      "x=18#ohm\n",
-      "e=3800#V\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(x/r)\n",
-      "vp=v/math.sqrt(3)\n",
-      "eb=e/math.sqrt(3)\n",
-      "alpha=theta\n",
-      "er=math.sqrt(vp**2+eb**2-(2*vp*eb*math.cos(theta)))\n",
-      "zs=math.sqrt(r**2+x**2)\n",
-      "ia=er/zs\n",
-      "pm_max=((eb*vp/zs)-(eb**2*r/zs**2))*3\n",
-      "cu_loss=3*ia**2*r\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*v*ia)\n",
-      "\n",
-      "#result\n",
-      "print \"maximum total mechanical power=\",pm_max,\"W\"\n",
-      "print \"current=\",ia,\"A\"\n",
-      "print \"pf=\",pf\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "maximum total mechanical power= 604356.888001 W\n",
-        "current= 151.417346198 A\n",
-        "pf= 0.857248980398\n"
-       ]
-      }
-     ],
-     "prompt_number": 235
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.32, Page Number:1521"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=415#V\n",
-      "e=520#V\n",
-      "z=complex(0.5,4)\n",
-      "loss=1000#W\n",
-      "\n",
-      "#calculations\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "er=math.sqrt(v**2+e**2-(2*v*e*math.cos(theta)))\n",
-      "zs=abs(z)\n",
-      "i=er/zs\n",
-      "il=math.sqrt(3)*i\n",
-      "pm_max=((e*v/zs)-(e**2*z.real/zs**2))*3\n",
-      "output=pm_max-loss\n",
-      "cu_loss=3*i**2*z.real\n",
-      "input_m=pm_max+cu_loss\n",
-      "pf=input_m/(math.sqrt(3)*il*v)\n",
-      "efficiency=output/input_m\n",
-      "\n",
-      "#result\n",
-      "print \"power output=\",output/1000,\"kW\"\n",
-      "print \"line current=\",il,\"A\"\n",
-      "print \"power factor=\",pf\n",
-      "print \"efficiency=\",efficiency*100,\"%\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "power output= 134.640174346 kW\n",
-        "line current= 268.015478962 A\n",
-        "power factor= 0.890508620247\n",
-        "efficiency= 78.4816159071 %\n"
-       ]
-      }
-     ],
-     "prompt_number": 240
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.33, Page Number:1524"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "v=400#V\n",
-      "inpt=37.3#kW\n",
-      "efficiency=0.88\n",
-      "z=complex(0.2,1.6)\n",
-      "pf=0.9\n",
-      "\n",
-      "#calculations\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=abs(z)\n",
-      "il=inpt*1000/(math.sqrt(3)*v*efficiency*pf)\n",
-      "izs=zs*il\n",
-      "theta=math.atan(z.imag/z.real)\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta+phi)))\n",
-      "input_m=inpt*1000/efficiency\n",
-      "cu_loss=3*il**2*z.real\n",
-      "pm=input_m-cu_loss\n",
-      "\n",
-      "#result\n",
-      "print \"induced emf=\",eb*math.sqrt(3),\"V\"\n",
-      "print \"total mechanical power=\",pm/1000,\"kW\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "induced emf= 494.75258624 V\n",
-        "total mechanical power= 39.6138268735 kW\n"
-       ]
-      }
-     ],
-     "prompt_number": 243
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.34, Page Number:1525"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "inpt=48#kW\n",
-      "v=693#V\n",
-      "pf=0.8\n",
-      "ratio=0.3\n",
-      "x=2#W/phase\n",
-      "\n",
-      "#calculations\n",
-      "il=inpt*1000/(math.sqrt(3)*v*pf)\n",
-      "vp=v/math.sqrt(3)\n",
-      "zs=x\n",
-      "izs=zs*il\n",
-      "theta=math.atan(float(\"inf\"))\n",
-      "phi=math.acos(pf)\n",
-      "eb=math.sqrt(vp**2+izs**2-(2*vp*izs*math.cos(theta-phi)))\n",
-      "i_cosphi=pf*il\n",
-      "bc=i_cosphi*x\n",
-      "eb=eb+(ratio*eb)\n",
-      "ac=math.sqrt(eb**2-bc**2)\n",
-      "oc=ac-vp\n",
-      "phi2=math.atan(oc/bc)\n",
-      "pf=math.cos(phi2)\n",
-      "i2=i_cosphi/pf\n",
-      "\n",
-      "#result\n",
-      "print \"current=\",i2,\"A\"\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "current= 46.3871111945 A\n",
-        "pf= 0.862084919821\n"
-       ]
-      }
-     ],
-     "prompt_number": 251
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 38.35, Page Number:1526"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "#variable declaration\n",
-      "load=60.0#kW\n",
-      "inpt=240.0#kW\n",
-      "pf=0.8\n",
-      "pf2=0.9\n",
-      "\n",
-      "#calculations\n",
-      "total_load=inpt+load\n",
-      "phi=math.acos(pf2)\n",
-      "kVAR=total_load*math.tan(phi)\n",
-      "#factory load\n",
-      "phil=math.acos(pf)\n",
-      "kVAR=inpt*math.tan(phil)\n",
-      "kVA=inpt/pf\n",
-      "kVAR1=total_load*math.sin(phil)\n",
-      "lead_kVAR=kVAR1-kVAR\n",
-      "#synchronous motor\n",
-      "phim=math.atan(lead_kVAR/load)\n",
-      "motorpf=math.cos(phim)\n",
-      "motorkVA=math.sqrt(load**2+lead_kVAR**2)\n",
-      "\n",
-      "#result\n",
-      "print \"leading kVAR supplied by the motor=\",motorkVA\n",
-      "print \"pf=\",pf"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "leading kVAR supplied by the motor= 60.0\n",
-        "pf= 0.8\n"
-       ]
-      }
-     ],
-     "prompt_number": 253
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_1.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_1.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_1.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_2.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_2.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_2.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_3.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_3.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_3.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_4.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_4.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_4.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_5.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_5.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_5.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_6.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_6.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_6.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_7.ipynb b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_7.ipynb
deleted file mode 100755
index e889465f..00000000
--- a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/chapter39_7.ipynb
+++ /dev/null
@@ -1,256 +0,0 @@
-{
- "metadata": {
-  "name": "",
-  "signature": "sha256:c262c33cbbcf1d1756b9358f8cf1d8ed92f53825858905e2598fd8e15870c7ca"
- },
- "nbformat": 3,
- "nbformat_minor": 0,
- "worksheets": [
-  {
-   "cells": [
-    {
-     "cell_type": "heading",
-     "level": 1,
-     "metadata": {},
-     "source": [
-      "Chapter 39: Special Machines"
-     ]
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.1, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable description\n",
-      "p=8.0 #number of poles\n",
-      "tp=5.0 #number of teeth for each pole\n",
-      "nr=50.0 #number of rotor teeth\n",
-      "\n",
-      "#calculation\n",
-      "ns=p*tp #number of stator teeth\n",
-      "B=((nr-ns)*360)/(nr*ns) #stepping angle\n",
-      "\n",
-      "#result\n",
-      "print \"stepping angle is \",B,\"degrees\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "stepping angle is  1.8 degrees\n"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.2, Page Number:1537"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=2.5\n",
-      "rn=25\n",
-      "f=3600\n",
-      "\n",
-      "#calculation\n",
-      "r=360/B\n",
-      "s=r*rn\n",
-      "n=(B*f)/360\n",
-      "\n",
-      "#result\n",
-      "print \"Resolution =\",int(r),\"steps/revolution\"\n",
-      "print \" Number of steps required for the shaft to make 25 revolutions =\",int(s)\n",
-      "print \" Shaft speed\", int(n),\"rps\"\n"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        " Resolution = 144 steps/revolution\n",
-        "Number of steps required for the shaft to make 25 revolutions = 3600\n",
-        "Shaft speed 25 rps\n"
-       ]
-      }
-     ],
-     "prompt_number": 14
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.3, Page Number:1544"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=15 #stepping angle\n",
-      "pn=3 #number of phases\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "\n",
-      "#number of stator teeth\n",
-      "ns1=((360*nr)/(360-(nr*B))) #ns>nr\n",
-      "ns2=((360*nr)/(360+(nr*B))) #nr>ns\n",
-      "\n",
-      "#result\n",
-      "print \"When ns>nr: ns= \",ns1\n",
-      "print \"When nr>ns: ns= \",ns2"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "When ns>nr: ns=  12\n",
-        "When nr>ns: ns=  6\n"
-       ]
-      }
-     ],
-     "prompt_number": 40
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.4, Page Number:1545"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "#variable declaration\n",
-      "B=1.8\n",
-      "pn=4\n",
-      "\n",
-      "#calculation\n",
-      "nr=360/(pn*B) #number of rotor teeth\n",
-      "ns=nr\n",
-      "\n",
-      "#result\n",
-      "print \"Number of rotor teeth = \",int(nr)\n",
-      "print \"Number of statot teeth = \",int(ns)"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "Number of rotor teeth =  50.0\n",
-        "Number of statot teeth =  50.0\n"
-       ]
-      }
-     ],
-     "prompt_number": 18
-    },
-    {
-     "cell_type": "heading",
-     "level": 2,
-     "metadata": {},
-     "source": [
-      "Example Number 39.5, Page Number:1555"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import math\n",
-      "\n",
-      "#variable declaration\n",
-      "er=20\n",
-      "\n",
-      "#calculation\n",
-      "a=40\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"a) For a=40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=(-40)\n",
-      "e2=er*math.cos(math.radians(a))\n",
-      "e1=er*math.cos(math.radians(a-120))\n",
-      "e3=er*math.cos(math.radians(a+120))\n",
-      "\n",
-      "#result\n",
-      "print \"b) For a=-40 degrees\"\n",
-      "print \"   e2s=\" ,e2,\"V\"\n",
-      "print \"   e1s=\" ,e1,\"V\"\n",
-      "print \"   e3s=\" ,e3,\"V\"\n",
-      "\n",
-      "#calculation\n",
-      "a=30\n",
-      "e12=math.sqrt(3)*er*math.cos(math.radians(a-150))\n",
-      "e23=math.sqrt(3)*er*math.cos(math.radians(a-30))\n",
-      "e31=math.sqrt(3)*er*math.cos(math.radians(a+90))\n",
-      "\n",
-      "#result\n",
-      "print \"c) For a=30 degrees\"\n",
-      "print \"   e12=\" ,e12,\"V\"\n",
-      "print \"   e23=\" ,e23,\"V\"\n",
-      "print \"   e31=\" ,e31,\"V\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "a) For a=40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= 3.47296355334 V\n",
-        "   e3s= -18.7938524157 V\n",
-        "b) For a=-40 degrees\n",
-        "   e2s= 15.3208888624 V\n",
-        "   e1s= -18.7938524157 V\n",
-        "   e3s= 3.47296355334 V\n",
-        "c) For a=30 degrees\n",
-        "   e12= -17.3205080757 V\n",
-        "   e23= 34.6410161514 V\n",
-        "   e31= -17.3205080757 V\n"
-       ]
-      }
-     ],
-     "prompt_number": 41
-    }
-   ],
-   "metadata": {}
-  }
- ]
-}
\ No newline at end of file
diff --git a/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter29example32.png b/A_Textbook_of_Electrical_Technology_:_AC_and_DC_Machines_(Volume_-_2)_by_A_K_Theraja_B_L_Thereja/screenshots/chapter29example32.png
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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 2 - Power Switching Devices & Their Characteristics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.1 page 67"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "VA = 1.10 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "V1=1    # V across SCR\n",
+    "IG=0    # A\n",
+    "Ih=2    # mA holding current\n",
+    "R=50    # ohm\n",
+    "\n",
+    "# Applying kirchoff law\n",
+    "#VA-(IAK*R)-V1=0\n",
+    "VA=(Ih*10**-3*R)+V1    # V (let IAK=Ih)\n",
+    "print 'VA = %.2f V'%(VA)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.2 page 67"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Minimum duration of gating pulse = 10 us\n"
+     ]
+    }
+   ],
+   "source": [
+    "diBYdt=1000    # A/s (rate of rise of current)\n",
+    "il=10    # mA (latching current = diBYdt * tp)\n",
+    "tp=il*10**-3/diBYdt    # s\n",
+    "print 'Minimum duration of gating pulse = %.f us'%(tp*10**6)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.3 page 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Gate power dissipation = 4 W\n",
+      "\n",
+      " Resistance to be connected = 14 ohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "m=16    #  V/A (gradient)\n",
+    "t_on=4    #  us\n",
+    "IG=500    #  mA\n",
+    "VS=15    #  V\n",
+    "\n",
+    "VG=m*IG/1000    #  V\n",
+    "#Load line equation\n",
+    "#VG=VS-IG*RS\n",
+    "RS=(VS-VG)/(IG/1000)     #  ohm\n",
+    "Pg=VS*(IG/1000)**2 # # W\n",
+    "print 'Gate power dissipation = %.f W'%(Pg)\n",
+    "print '\\n Resistance to be connected = %.f ohm'%(RS)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.4 page 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Value of resistance to be added in series = 44.11 ohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from numpy import roots\n",
+    "# VG=0.5+8*IG -- eqn(1)\n",
+    "f=400# # Hz\n",
+    "delta=0.1 # # (Duty Cycle)\n",
+    "P=0.5    # W\n",
+    "VS=12    #  V\n",
+    "\n",
+    "Tp=1/f*10**6    #  us\n",
+    "# P= VG*IG -- eqn(2)\n",
+    "# solving eqn  1 and 2\n",
+    "#8*IG*IG**2+0.5*IG-P=0\n",
+    "p=[8, 0.5, -P] # polynomial for IG\n",
+    "IG=roots(p)     #  A \n",
+    "IG=IG[1]     #  A (discarding -ve value)\n",
+    "VG=0.5+8*IG    #  V\n",
+    "# VS=VG+IG*RS\n",
+    "RS=(VS-VG)/IG\n",
+    "print 'Value of resistance to be added in series = %.2f ohm'%(RS)\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.5 page 69"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Value of resistance to be connected in series = 6.97 ohm\n",
+      "\n",
+      " Triggering frequency = 5.00 kHz\n",
+      "\n",
+      " Duty Cycle = 0.1 \n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "# VG=10*IG -- eqn(1)\n",
+    "PGM=5    #  W\n",
+    "PGav=.5    #  W\n",
+    "VS=12    #  V\n",
+    "Tp=20    #  us\n",
+    "\n",
+    "# PGM = VG*IG where VG=10*IG\n",
+    "\n",
+    "IG=sqrt(PGM/10)    #  A\n",
+    "VG=10*IG    #  V\n",
+    "# During the application of pulse VS = VG+(IG*RS)\n",
+    "RS=(VS-VG)/IG     #  ohm\n",
+    "f=PGav/(PGM*Tp*10**-6)/1000    #  kHz\n",
+    "delta=f*1000*Tp*10**-6    #  Duty Cycle\n",
+    "print 'Value of resistance to be connected in series = %.2f ohm'%(RS)\n",
+    "print '\\n Triggering frequency = %.2f kHz'%(f)\n",
+    "print '\\n Duty Cycle = %.1f '%(delta)\n",
+    "# Note : ans in the textbook is not accurate."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.6 page 70"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Value of R = 31.25 kohm\n",
+      "\n",
+      " Value of C = 1.20e-07 F\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "VS=3    #  kV\n",
+    "IS=750    #  A\n",
+    "\n",
+    "VD=800    #  V\n",
+    "ID=175    #  A\n",
+    "dr=30/100    #  de-rating factor\n",
+    "IB=8    # mA\n",
+    "delQ=30    #  u Coulomb\n",
+    "# dr = 1-IS/np*ID\n",
+    "np = round(IS/(1-dr)/(ID)) # # no. of parallel string\n",
+    "ns = round(VS*1000/(1-dr)/(VD)) # # no. of series string\n",
+    "R=(ns*VD-VS*1000)/(ns-1)/(IB/1000)/1000    # kohm\n",
+    "C=(ns-1)*delQ*10**-6/(ns*VD-VS*1000)\n",
+    "print 'Value of R = %.2f kohm'%(R)\n",
+    "print '\\n Value of C = %.2e F'%(C)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.7 page 71"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " no. of series connection = 7\n",
+      "\n",
+      " no. of parallel connection = 5\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import ceil\n",
+    "VS=4    #  kV\n",
+    "IS=800    #  A\n",
+    "\n",
+    "VD=800    #  V\n",
+    "ID=200    #  A\n",
+    "dr=20/100    #  de-rating factor\n",
+    "# for series connection\n",
+    "ns = ceil(VS*1000/(1-dr)/(VD)) # # no. of series string\n",
+    "# for parallel connection\n",
+    "np = round(IS/(1-dr)/(ID)) # # no. of parallel string\n",
+    "print '\\n no. of series connection = %d'%(ns)\n",
+    "print '\\n no. of parallel connection = %d'%(np)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.8 page 72"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " Series resistance = 0.007 ohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "IS1=100    #  A\n",
+    "IS2=150    #  A\n",
+    "vd1=2.1    #  V\n",
+    "vd2=1.75    #  V\n",
+    "I=250    #  A\n",
+    "\n",
+    "rf1=vd1/IS1    #  ohm\n",
+    "rf2=vd2/IS2    #  ohm\n",
+    "# Equating voltage drops\n",
+    "# vd1+IS1*re = vd2+IS2*re\n",
+    "re=(vd1-vd2)/(IS2-IS1)\n",
+    "print ' Series resistance = %.3f ohm'%(re)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.9 page 72"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Average power loss = 34.8 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import pi\n",
+    "Vf1=1    #  V\n",
+    "If1=0    # A\n",
+    "Vf2=1.9    #  V\n",
+    "If2=60    # A\n",
+    "IT=20*pi    #  A\n",
+    "# PAV = 1/T*integrate(VT*IT,0,T)*dt = ITAV+0.015*IRMS**2\n",
+    "ITAV=IT/pi    # A\n",
+    "ITRMS=IT/2    #  A\n",
+    "dt=ITAV+0.015*ITRMS**2    #  W\n",
+    "print 'Average power loss = %.1f W'%(dt)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.10 page 73"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Minimum gate pulse width = 8.7 us\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "R=10    #  ohm\n",
+    "L=0.1    #  H\n",
+    "delta_i=20/1000    #  A\n",
+    "Vs=230    #  V4\n",
+    "f=50    #  Hz\n",
+    "theta=45    # degree\n",
+    "\n",
+    "delta_t = L*delta_i/Vs# # s\n",
+    "delta_t = delta_t*10**6    #  us\n",
+    "print 'Minimum gate pulse width = %.1f us'%(delta_t)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.11 page 73"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "gate source resistance = 2.0 kohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "m=3*10**3    #  gradient (VG/IG)\n",
+    "VS=10    #  V\n",
+    "PG=0.012    #  W\n",
+    "# IG = VG/m & PG=VG*IG\n",
+    "VG=sqrt(PG*m)\n",
+    "IG=VG/m # # A\n",
+    "RS=(VS-VG)/IG/1000    #  kohm\n",
+    "print 'gate source resistance = %.1f kohm'%(RS)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.12 page 74"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Value of resistance = 6.82 kohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "VS=300    #  V\n",
+    "delta_i = 50/1000    #  A\n",
+    "R=60    #  ohm\n",
+    "L=2    #  H\n",
+    "TP=40*10**-6    #  s\n",
+    "\n",
+    "I1=VS/L*TP    #  A (at the end of pulse)\n",
+    "# as I1 << delta_i\n",
+    "I2=delta_i    #  A (anode current with RL load)\n",
+    "\n",
+    "Rdash = VS/(I2-I1)/1000    #  kohm\n",
+    "print 'Value of resistance = %.2f kohm'%(Rdash)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.13 page 74"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "For half sine wave current : \n",
+      "\n",
+      "(i) Average ON State current  = 31.83 A\n",
+      "\n",
+      "(ii) Average ON State current  = 22.51 A\n",
+      "\n",
+      "(iii) Average ON State current  = 12.54 A\n",
+      "\n",
+      "\n",
+      " For rectangular wave current : \n",
+      "\n",
+      "(i) Average ON State current  = 35.36 A\n",
+      "\n",
+      "(ii) Average ON State current  = 25.00 A\n",
+      "\n",
+      "(i) Average ON State current  = 14.43 A\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import pi,sqrt\n",
+    "Im=50    #  A\n",
+    "\n",
+    "print 'For half sine wave current : \\n'\n",
+    "# theta=180    #  degree\n",
+    "theta=180    #  degree\n",
+    "Iav=Im/pi    #  A\n",
+    "Irms=Im/2    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(i) Average ON State current  = %.2f A\\n'%(ITav)    \n",
+    "\n",
+    "# theta=90    #  degree\n",
+    "theta=90    #  degree\n",
+    "Iav=Im/2/pi    #  A\n",
+    "Irms=Im/2/sqrt(2)    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(ii) Average ON State current  = %.2f A\\n'%(ITav)    \n",
+    "\n",
+    "# theta=180    #  degree\n",
+    "theta=180    #  degree\n",
+    "Iav=Im*0.0213    #  A\n",
+    "Irms=Im*0.0849    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(iii) Average ON State current  = %.2f A\\n'%(ITav)    \n",
+    "\n",
+    "print '\\n For rectangular wave current : \\n'\n",
+    "# theta=180    #  degree\n",
+    "theta=180    #  degree\n",
+    "Iav=Im/2    #  A\n",
+    "Irms=Im/sqrt(2)    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(i) Average ON State current  = %.2f A\\n'%(ITav)    \n",
+    "\n",
+    "# theta=90    #  degree\n",
+    "theta=90    #  degree\n",
+    "Iav=Im/4    #  A\n",
+    "Irms=Im/2    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(ii) Average ON State current  = %.2f A\\n'%(ITav)    \n",
+    "\n",
+    "# theta=180    #  degree\n",
+    "theta=180    #  degree\n",
+    "Iav=Im/12    #  A\n",
+    "Irms=Im/2/sqrt(3)    #  A\n",
+    "FF=Irms/Iav    #  form factor\n",
+    "ITav=Im/FF # # A\n",
+    "print '(i) Average ON State current  = %.2f A\\n'%(ITav)    "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.14 page 76"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Value of L = 16.67 uH\n",
+      "\n",
+      " Value of R = 3.3 ohm\n",
+      "\n",
+      " Value of Ip = 175.0 A is greater than permissible peak current = 125.0 A\n",
+      " change the value of Rs\n",
+      "\n",
+      " Value of C = 0.78 uF\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "VS=500    #  V\n",
+    "IP=250    #  A\n",
+    "diBYdt=60    #  A/us\n",
+    "dvaBYdt=200    #  V/us\n",
+    "RL=20    #  ohm\n",
+    "r=0.65    #  ohm\n",
+    "eps=0.65     #  damping ratios\n",
+    "\n",
+    "F=2    #  saftety factor\n",
+    "IP=IP/2    #  A\n",
+    "diBYdt=60/2    #  A/us\n",
+    "dvaBYdt=200/2    #  V/us\n",
+    "L=VS/diBYdt    #  uH\n",
+    "R=L*10**6/VS*dvaBYdt/10**6    #  ohm\n",
+    "print 'Value of L = %.2f uH'%(L)\n",
+    "print '\\n Value of R = %.1f ohm'%(R)\n",
+    "\n",
+    "Ip=VS/RL+VS/R    #  A\n",
+    "if Ip > IP :\n",
+    "    print '\\n Value of Ip = %.1f A is greater than permissible peak current = %.1f A\\n change the value of Rs'%(Ip,IP)\n",
+    "    Rs=6    # ohm\n",
+    "\n",
+    "Ip=VS/RL+VS/Rs    #  A\n",
+    "Cs=(2*eps/Rs)**2*L    #  uF\n",
+    "print '\\n Value of C = %.2f uF'%(Cs)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 2.15 page 77"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "I2t rating = 45000 A**2/s\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import ceil,sqrt\n",
+    "Isb=3000    #  A\n",
+    "f=50    #  Hz\n",
+    "I=sqrt((Isb**2*1/2/f)*f)     #  A\n",
+    "I2t=I**2/2/f    #  A**2/s\n",
+    "print 'I2t rating = %d A**2/s'%(ceil(I2t))"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter3.ipynb b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter3.ipynb
new file mode 100644
index 00000000..ee71b34f
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter3.ipynb
@@ -0,0 +1,893 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 3 - AC to DC Converters"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.1 page 117"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Power delivered = 199.11 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "R=100    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha=45    #  degree\n",
+    "\n",
+    "Vo=Vs*sqrt(2)/2/pi*(1+cos(pi/180*alpha))    #  V\n",
+    "Io=Vo/R    #  A\n",
+    "Vor=Vs/sqrt(2)*sqrt(1/180*((180-alpha)+sin(pi/180*2*alpha)/2))    #  V\n",
+    "Ior=Vor/R    #  A\n",
+    "P=Ior**2*R    #  W\n",
+    "print 'Power delivered = %.2f W'%(P)\n",
+    "\n",
+    "#Ans in the textbook is not accurate."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.2 page 118"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Power supplied to battery = 593 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,asin,cos,sin\n",
+    "\n",
+    "R=10    #  ohm\n",
+    "E=165    #  V\n",
+    "#vt=330*sin(314*t)\n",
+    "Vm=330    #  V\n",
+    "f=314/2/pi    #  Hz\n",
+    "alpha1=asin(E/Vm)    #  radian\n",
+    "alpha2=pi-alpha1    #  radian\n",
+    "Io=1/2/pi/R*(2*Vm*cos(alpha1)-E*(alpha2-alpha1))    #  A\n",
+    "P=E*Io    #  W\n",
+    "\n",
+    "print 'Power supplied to battery = %d W'%(P)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.3 page 119"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "part (a)\n",
+      "\n",
+      " dc voltage Vo = 88.3 V\n",
+      "\n",
+      " & Current Io = 4.415 A\n",
+      "\n",
+      "\n",
+      " part (b)\n",
+      "\n",
+      " rms voltage Vor = 154.943 V\n",
+      "\n",
+      " & Current Ior = 7.747 A\n",
+      "\n",
+      "\n",
+      " part (c)\n",
+      "\n",
+      " dc Power = 389.85 W\n",
+      "\n",
+      " ac Power = 1200.37 W\n",
+      "\n",
+      " Rectification efficiency = 0.3248\n",
+      "\n",
+      "\n",
+      " part (d)\n",
+      "\n",
+      " Form factor = 1.755 \n",
+      "\n",
+      " Ripple factor = 1.442 \n",
+      "\n",
+      "\n",
+      " part (e)\n",
+      "\n",
+      " VA rating = 1781.8 VA\n",
+      "\n",
+      " Transformer Utilization factor = 0.2188\n",
+      "\n",
+      "\n",
+      " part (f)\n",
+      "\n",
+      " Peak inverse voltage = 325 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "#v2t = 325*sin(w*t)\n",
+    "R=20    #  ohm\n",
+    "alfa=45    #  degree\n",
+    "vm=325    #  V\n",
+    "V=230    #  V\n",
+    "print 'part (a)\\n'\n",
+    "Vo=vm/2/pi*(1+cos(pi/180*alfa))     #  V\n",
+    "Io=Vo/R    #  A\n",
+    "print ' dc voltage Vo = %.1f V'%(Vo)\n",
+    "print '\\n & Current Io = %.3f A'%(Io)\n",
+    "print '\\n\\n part (b)\\n'\n",
+    "Vor=vm/2/sqrt(pi)*sqrt((pi-pi/180*alfa)+1/2*sin(pi/180*2*alfa))    #  V\n",
+    "Ior=Vor/R    #  A\n",
+    "print ' rms voltage Vor = %.3f V'%(Vor)\n",
+    "print '\\n & Current Ior = %.3f A'%(Ior)\n",
+    "print '\\n\\n part (c)'\n",
+    "Pdc=Vo*Io    #  W\n",
+    "Pac=Vor*Ior    #  W\n",
+    "eta=Pdc/Pac    #  rectification efficiency\n",
+    "print \"\\n dc Power = %.2f W\"%(Pdc)\n",
+    "print \"\\n ac Power = %.2f W\"%(Pac)\n",
+    "print \"\\n Rectification efficiency = %.4f\"% (eta)\n",
+    "print '\\n\\n part (d)'\n",
+    "FF=Vor/Vo    #  form factor\n",
+    "RF=sqrt(FF**2-1)\n",
+    "print '\\n Form factor = %.3f '%(FF)\n",
+    "print '\\n Ripple factor = %.3f '%(RF)\n",
+    "print '\\n\\n part (e)'\n",
+    "VA=V*Ior    #  VA\n",
+    "TUF=Pdc/V/Ior    #  Transformer Utilization factor\n",
+    "print \"\\n VA rating = %.1f VA\"%(VA)\n",
+    "print \"\\n Transformer Utilization factor = %.4f\"%TUF\n",
+    "print '\\n\\n part (f)'\n",
+    "Vp=vm    #  V\n",
+    "print \"\\n Peak inverse voltage = %d V\"%Vp"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.4 page 120"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(a) Average value of current = 3.60 A\n",
+      "\n",
+      " (b) Power supplied to battery = 593 W\n",
+      "\n",
+      " (c) Power dissipated in the resistor = 1216.14 W\n",
+      "\n",
+      " (d) Power factor = 0.7043\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin,asin\n",
+    "\n",
+    "R=10    #  ohm\n",
+    "E=165    #  V\n",
+    "#vt=330*sin(314*t)\n",
+    "Vm=330    #  V\n",
+    "Vs=233    #  V\n",
+    "f=314/2/pi    #  Hz\n",
+    "theta1=asin(E/Vm)    #  radian\n",
+    "#alpha2=pi-alpha1    #  radian\n",
+    "Io=1/2/pi/R*(2*Vm*cos(theta1)-E*(pi-2*theta1))    #  A\n",
+    "print '(a) Average value of current = %.2f A'%(Io)\n",
+    "P=E*Io    #  W\n",
+    "print '\\n (b) Power supplied to battery = %d W'%(P)\n",
+    "Ior=sqrt(1/2/pi/R**2*((pi-2*theta1)*(Vs**2+E**2)+Vm**2*sin(2*theta1)-4*Vm*E*cos(theta1)))    #  A\n",
+    "Pr=Ior**2*R    #  W\n",
+    "print '\\n (c) Power dissipated in the resistor = %.2f W'%(Pr)\n",
+    "pf=(Pr+P)/Vs/Ior    #  power factor\n",
+    "print '\\n (d) Power factor = %.4f'%(pf)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.5 page 122"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Average load voltage = 193.2 V\n",
+      "\n",
+      " Average load current = 9.66 A\n",
+      "\n",
+      " rms load current = 11.33 A\n",
+      "\n",
+      " Average thyristor current = 4.83 A\n",
+      "\n",
+      " rms thyristor current = 8.014 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=20    #  ohm\n",
+    "V=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha=30    #  degree\n",
+    "Vm=V*sqrt(2)    # V\n",
+    "Vo=Vm/pi*(1+cos(alpha*pi/180))    #  V\n",
+    "print 'Average load voltage = %.1f V'%(Vo)\n",
+    "Io=Vo/R    #  A\n",
+    "print '\\n Average load current = %.2f A'%( Io)\n",
+    "Vor=V/sqrt(pi)*sqrt((pi-alpha*pi/180)+sin(2*alpha*pi/180)/2)    #  V\n",
+    "Ior=Vor/R    #  A\n",
+    "print '\\n rms load current = %.2f A'%( Ior)\n",
+    "Iav=Io/2    # A\n",
+    "print '\\n Average thyristor current = %.2f A'%( Iav)\n",
+    "Irms=Ior/sqrt(2)    #  A\n",
+    "print '\\n rms thyristor current = %.3f A'%( Irms)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.6 page 122"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Average load current = 4.642 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=10    #  ohm\n",
+    "L=100/1000    #  H\n",
+    "E=100    #  V\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 45    #  degree\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=2*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "Io=(Vo-E)/R    #  A\n",
+    "print 'Average load current = %.3f A'%(Io)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.7 page 123"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " Average load voltage = 179.33 V\n",
+      "\n",
+      " Average load current = 89.67 A\n",
+      "\n",
+      " Power factor = 0.7797\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=2    #  ohm\n",
+    "L=0.3    #  H\n",
+    "E=100    #  V\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 30    #  degree\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=2*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "print ' Average load voltage = %.2f V'%( Vo)\n",
+    "Io=(Vo)/R    #  A\n",
+    "print '\\n Average load current = %.2f A'%( Io)\n",
+    "Is=Io    #  A\n",
+    "Is1=4*Io/pi/sqrt(2)    #  A\n",
+    "PF=Vo*Io/Vs/Is    #  power factor\n",
+    "print '\\n Power factor = %.4f'%(PF)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.8 page 123"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " Average load voltage = 176.75 V\n",
+      "\n",
+      " Average load current = 33.35 A\n",
+      "\n",
+      " Power factor = 0.7685\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=5    #  ohm\n",
+    "L=1    #  H\n",
+    "E=10    #  V\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 45    #  degree\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=Vm/pi*(1+cos(alpha*pi/180))    #  V\n",
+    "print ' Average load voltage = %.2f V'%( Vo)\n",
+    "Io=(Vo-E)/R    #  A\n",
+    "print '\\n Average load current = %.2f A'%( Io)\n",
+    "PF=(Io**2*R+E*Io)/Vs/Io    #  power factor\n",
+    "print '\\n Power factor = %.4f'%(PF)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.9 page 124"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " (i) Average voltage across 50 ohm resistor = 179.33 V\n",
+      "\n",
+      " (ii) rms current = 2.5361 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=50    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 30    #  degree\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=2*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "print ' (i) Average voltage across 50 ohm resistor = %.2f V'%( Vo)\n",
+    "Io=(Vo)/R    #  A\n",
+    "Ior=Io/sqrt(2)    #  A\n",
+    "print '\\n (ii) rms current = %.4f A'%( Ior)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.10 page 124"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "emf on load side = 123.54 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=2    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 120    #  degree\n",
+    "Ia=10    #  A\n",
+    "\n",
+    "Vo=2*sqrt(2)*Vs*cos(alpha*pi/180)/pi\n",
+    "V=Ia*R-Vo    #  V\n",
+    "print 'emf on load side = %.2f V'%( V)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.11 page 125"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "part(i)\n",
+      "\n",
+      " dc output voltage = 146.4 V\n",
+      "\n",
+      " Active power = 732.1 W\n",
+      "\n",
+      " Reactive power = 732.1 VAR\n",
+      "\n",
+      "\n",
+      " part(ii)\n",
+      "\n",
+      " dc output voltage = 176.7 V\n",
+      "\n",
+      " Active power = 1066.8 W\n",
+      "\n",
+      " Reactive power = -441.9 VAR\n",
+      "\n",
+      "\n",
+      " part(iii)\n",
+      "\n",
+      " Average load voltage = 88 V\n",
+      "\n",
+      " Average load current = 3.02 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "Vs=230    #  V\n",
+    "Io=5    #  A\n",
+    "alpha = 45    #  degree\n",
+    "print 'part(i)'\n",
+    "Vo=2*sqrt(2)*Vs/pi*cos(alpha*pi/180)    #  V\n",
+    "print '\\n dc output voltage = %.1f V'%(Vo)\n",
+    "Pi=Vo*Io    #  W\n",
+    "print '\\n Active power = %.1f W'%(Pi)\n",
+    "Qi=2*sqrt(2)*Vs/pi*sin(alpha*pi/180)*Io    #  VAR\n",
+    "print '\\n Reactive power = %.1f VAR'%(Qi)\n",
+    "print '\\n\\n part(ii)'\n",
+    "R=Vo/Io    #  ohm\n",
+    "Vo=sqrt(2)*Vs/pi*(1+cos(alpha*pi/180))    #  V\n",
+    "print '\\n dc output voltage = %.1f V'%(Vo)\n",
+    "Io=Vo/R    #  A\n",
+    "Pi=Vo*Io    #  W\n",
+    "print '\\n Active power = %.1f W'%(Pi)\n",
+    "Qi=sqrt(2)*Vs/pi*sin(alpha*pi/4)*Io    #  VAR\n",
+    "print '\\n Reactive power = %.1f VAR'%(Qi)\n",
+    "print '\\n\\n part(iii)'\n",
+    "Vo=sqrt(2)*Vs/pi/2*(1+cos(alpha*pi/180))    #  \n",
+    "print '\\n Average load voltage = %.0f V'%(Vo)\n",
+    "Io=Vo/R    #  A\n",
+    "print '\\n Average load current = %.2f A'%(Io)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.12 page 126"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Average load voltage = 467.818 V\n",
+      "\n",
+      " Average load current = 23.391 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "R=20    #  ohm\n",
+    "Vs=400    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 30    #  degree\n",
+    "\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=3*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "Io=Vo/R    #  A\n",
+    "print '\\n Average load voltage = %.3f V'%(Vo)\n",
+    "print '\\n Average load current = %.3f A'%(Io)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.13 page 126"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " (i)\n",
+      "\n",
+      " Output voltage = 270 V\n",
+      "\n",
+      " Output power = 27009 W\n",
+      "\n",
+      "\n",
+      " (ii)\n",
+      "\n",
+      " average current through thyristor = 33.33 A\n",
+      "\n",
+      " rms current through thyristor = 57.74 A\n",
+      "\n",
+      " peak current through thyristor = 100.00 A\n",
+      "\n",
+      "\n",
+      " (iii)\n",
+      "\n",
+      " PIV of thyristor = 565.7 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "n=3    #  no. of phase\n",
+    "Vs=400    #  V\n",
+    "f=50    #  Hz\n",
+    "Io=100    #  A\n",
+    "alpha = 60    #  degree\n",
+    "\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=n*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "Po=Vo*Io    #  W\n",
+    "print ' (i)'\n",
+    "print '\\n Output voltage = %.0f V'%(Vo)\n",
+    "print '\\n Output power = %.0f W'%(Po)\n",
+    "print '\\n\\n (ii)'\n",
+    "Iav=Io*2*pi/3/2/pi    #  A\n",
+    "print '\\n average current through thyristor = %.2f A'%( Iav)\n",
+    "Ior=sqrt(Io**2*2*pi/3/2/pi)    #  A\n",
+    "print '\\n rms current through thyristor = %.2f A'%( Ior)\n",
+    "Ip=Io    # A\n",
+    "print '\\n peak current through thyristor = %.2f A'%( Ip)\n",
+    "print '\\n\\n (iii)'\n",
+    "PIV=sqrt(2)*Vs    # V\n",
+    "print '\\n PIV of thyristor = %.1f V'%(PIV)\n",
+    "# Ans in the book is not accurate."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.14 page 127"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Average load voltage = 467.818 V\n",
+      "\n",
+      " Average load current = 7.8 A\n",
+      "\n",
+      " input power factor = 0.6752\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "n=3    #  no. of phase\n",
+    "R=60    #  ohm\n",
+    "Vs=400    #  V\n",
+    "alpha = 30    #  degree\n",
+    "\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=3*Vm/pi*cos(alpha*pi/180)    #  V\n",
+    "Io=Vo/R    #  A\n",
+    "P=Io**2*R    #  W\n",
+    "pf=P/sqrt(3)/Vs/Io    #  power factor\n",
+    "\n",
+    "print '\\n Average load voltage = %.3f V'%(Vo)\n",
+    "print '\\n Average load current = %.1f A'%(Io)\n",
+    "print '\\n input power factor = %.4f'%(pf)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.15 page 127"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Average load voltage = 461.08 V\n",
+      "\n",
+      " Average load current = 9.22 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin\n",
+    "\n",
+    "n=3    #  no. of phase\n",
+    "R=50    #  ohm\n",
+    "Vs=400    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 45    #  degree\n",
+    "\n",
+    "Vm=Vs*sqrt(2)    #  V\n",
+    "Vo=3*Vm/2/pi*(1+cos(alpha*pi/180))    #  V\n",
+    "Io=Vo/R    #  A\n",
+    "print '\\n Average load voltage = %.2f V'%(Vo)\n",
+    "print '\\n Average load current = %.2f A'%(Io)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.16 page 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Firing angle = 33.59 degree\n",
+      "\n",
+      " Overlap angle = 10.20 degree\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin,acos\n",
+    "\n",
+    "n=3    #  no. of phase\n",
+    "Vs=400    #  V\n",
+    "f=50    #  Hz\n",
+    "Ls=5/1000    #  H\n",
+    "Io=20    #  A\n",
+    "Ri=1    #  ohm\n",
+    "Vdc=400    #  V\n",
+    "\n",
+    "Vo=Vdc+Io*Ri    #  V\n",
+    "# Vo=3*Vm/pi*cos(alpha*pi/180)-3*2*pi*f*Ls/pi*Io\n",
+    "Vm=sqrt(2)*Vs    #  V\n",
+    "alpha=acos((Vo+3*2*pi*f*Ls/pi*Io)/(3*Vm/pi))*180/pi    #  degree\n",
+    "\n",
+    "# Vo=3*Vm/pi*cos((alpha+mu)*pi/180)-3*2*pi*f*Ls/pi*Io\n",
+    "mu=acos((Vo-3*2*pi*f*Ls/pi*Io)/(3*Vm/pi))*180/pi-alpha    #  degree\n",
+    "print '\\n Firing angle = %.2f degree'%(alpha)\n",
+    "print '\\n Overlap angle = %.2f degree'%(mu)\n",
+    "# ans in the textbook is not accurate."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 3.17 page 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      " Load resistance = 36 ohm\n",
+      "\n",
+      " Source inductance = 7.3 mH\n",
+      "\n",
+      " Overlap angle = 6 degree\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,cos,sin,acos\n",
+    "\n",
+    "n=3    #  no. of phase\n",
+    "Vs=400    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = pi/4    #  radian\n",
+    "Io=10    #  A\n",
+    "Vo=360    #  V\n",
+    "\n",
+    "# Vo=n*Vs*sqrt(2)/pi/sqrt(2)-3*2*pi*f*Ls*Io/pi\n",
+    "Ls=(n*Vs*sqrt(2)/pi/sqrt(2)-Vo)/(3*2*pi*f)/(Io/pi)*1000    #  mH\n",
+    "R=Vo/Io    #  ohm\n",
+    "print ' Load resistance = %.f ohm'%(R)\n",
+    "print '\\n Source inductance = %.1f mH'%(Ls)\n",
+    "# Vo = n*Vs*sqrt(2)/pi*cos(alpha+mu)+3*2*pi*f*Ls*Io/pi\n",
+    "mu=acos((Vo-3*2*pi*f*Ls/1000*Io/pi)/(n*Vs*sqrt(2)/pi))-alpha    #  radian\n",
+    "mu=mu*180/pi    #  degree\n",
+    "print '\\n Overlap angle = %.d degree'%(mu)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter4.ipynb b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter4.ipynb
new file mode 100644
index 00000000..975b27ec
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter4.ipynb
@@ -0,0 +1,327 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 4 - AC to AC Converters"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.1 page 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " rms load voltage = 101.70 V\n",
+      "\n",
+      " rms load current = 20.34 A\n",
+      "\n",
+      " rms thyristor current = 14.38 A\n",
+      "\n",
+      " input power factor = 0.442 \n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin\n",
+    "R=5    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 120    #  degree\n",
+    "\n",
+    "Vor=Vs*sqrt(1/pi*(pi-alpha*pi/180+sin(2*alpha*pi/180)/2))    #  V\n",
+    "print '\\n rms load voltage = %.2f V'%( Vor)\n",
+    "Ior=Vor/R    #  A\n",
+    "print '\\n rms load current = %.2f A'%( Ior)\n",
+    "Irms=Ior/sqrt(2)    # A\n",
+    "print '\\n rms thyristor current = %.2f A'%( Irms)\n",
+    "pf=sqrt(1/pi*((pi-alpha*pi/180)+sin(2*alpha*pi/180)/2))    #  power factor\n",
+    "print '\\n input power factor = %.3f '%(pf)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.2 page 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " (a) rms output voltage = 138 V\n",
+      "\n",
+      " (b) Power output to load = 1904.4 W\n",
+      "\n",
+      " (c) Power input to regulator = 1904.4 W\n",
+      "\n",
+      " (d) input power factor = 0.6 \n",
+      "\n",
+      " (e) average scr current = 3.727 A\n",
+      "\n",
+      "     rms scr current = 9.758 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin\n",
+    "R=10    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "nc=18    #  conducting cycles\n",
+    "noff=32    #  off cycles\n",
+    "\n",
+    "k=nc/(nc+noff)    #  duty ratio\n",
+    "Vor=Vs*sqrt(k)    #  V\n",
+    "Po=Vor**2/R    #  W\n",
+    "Pi=Po    #  W (losses are negligble)\n",
+    "Ior=Vor/R    # A\n",
+    "pf=Po/Vs/Ior    # W\n",
+    "Im=Vs*sqrt(2)/R    # A\n",
+    "Irms=Im*sqrt(k)/2    # A\n",
+    "Iav=k*Im/pi    # A\n",
+    "print '\\n (a) rms output voltage = %.0f V'%( Vor)\n",
+    "print '\\n (b) Power output to load = %.1f W'%( Po)\n",
+    "print '\\n (c) Power input to regulator = %.1f W'%( Pi)\n",
+    "print '\\n (d) input power factor = %.1f '%(pf)\n",
+    "print '\\n (e) average scr current = %.3f A'%( Iav)\n",
+    "print '\\n     rms scr current = %.3f A'%( Irms)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.3 page 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " rms load voltage = 162.63 V\n",
+      "\n",
+      " rms load current = 16.26 A\n",
+      "\n",
+      " power input = 2645.00 W\n",
+      "\n",
+      " load power factor = 0.7 \n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin\n",
+    "R=10    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 90    #  degree\n",
+    "\n",
+    "Vor=Vs*sqrt(1/pi*(pi-alpha*pi/180+sin(2*alpha*pi/180)/2))    #  V\n",
+    "Ior=Vor/R    #  A\n",
+    "P=Ior**2*R    #  W\n",
+    "pf=Vor/Vs    #  power factor\n",
+    "print '\\n rms load voltage = %.2f V'%( Vor)\n",
+    "print '\\n rms load current = %.2f A'%( Ior)\n",
+    "print '\\n power input = %.2f W'%( P)\n",
+    "print '\\n load power factor = %.1f '%(pf)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.4 page 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " rms load voltage = 219.30 V\n",
+      "\n",
+      " rms load current = 7.31 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin\n",
+    "\n",
+    "R=30    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "alpha = 45    #  degree\n",
+    "\n",
+    "Vor=Vs*sqrt(1/pi*(pi-alpha*pi/180+sin(2*alpha*pi/180)/2))    #  V\n",
+    "Ior=Vor/R    #  A\n",
+    "print '\\n rms load voltage = %.2f V'%( Vor)\n",
+    "print '\\n rms load current = %.2f A'%( Ior)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.5 page 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " max load voltage = 230.00 V\n",
+      "\n",
+      " max load current = 16.263 A\n",
+      "\n",
+      " range of delay angle = 0 to 45\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin,tan\n",
+    "\n",
+    "R=10    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "fi = 45    #  degree\n",
+    "\n",
+    "Vmax=Vs    #  V(max supply voltage)\n",
+    "XL=R*tan(fi*pi/180)    #  ohm\n",
+    "Z=XL*sqrt(2)    #  ohm\n",
+    "Imax=Vs/Z    # A\n",
+    "\n",
+    "print '\\n max load voltage = %.2f V'%( Vmax)\n",
+    "print '\\n max load current = %.3f A'%( Imax)\n",
+    "print '\\n range of delay angle = %d to %d'%(0,fi)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 4.7 page 161"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " (i) control range of firing angle = 53.13 to pi\n",
+      "\n",
+      " (ii) max rms load current = 46 A\n",
+      "\n",
+      " (iii) max power input to load = 6348 W\n",
+      "\n",
+      " (iv) max power factor = 0.6 \n",
+      "\n",
+      " (v) max rms thyristor current = 32.527 A\n",
+      "\n",
+      "     max average thyristor current = 20.718 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,pi,sin,atan\n",
+    "\n",
+    "R=3    #  ohm\n",
+    "wL=4    # ohm\n",
+    "Vs=230    #  V\n",
+    "f=50    #  Hz\n",
+    "\n",
+    "fi=atan(wL/R)*180/pi    # degree\n",
+    "print '\\n (i) control range of firing angle = %.2f to pi'%(fi)\n",
+    "Imax=Vs/sqrt(R**2+wL**2)    #  A\n",
+    "print '\\n (ii) max rms load current = %.f A'%( Imax)\n",
+    "Pmax=Imax**2*R    # W\n",
+    "print '\\n (iii) max power input to load = %.f W'%( Pmax)\n",
+    "pf_max=Pmax/Vs/Imax    #  power factor\n",
+    "print '\\n (iv) max power factor = %.1f '%( pf_max)\n",
+    "Ithrms=Imax/sqrt(2)    #  A\n",
+    "Ithav=Ithrms/1.57    #  A\n",
+    "print '\\n (v) max rms thyristor current = %.3f A'%( Ithrms)\n",
+    "print '\\n     max average thyristor current = %.3f A'%( Ithav)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter5.ipynb b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter5.ipynb
new file mode 100644
index 00000000..4b5039f8
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter5.ipynb
@@ -0,0 +1,210 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 5 - DC to DC Converters (Choppers)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 5.1 page 184"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Average load current = 9.2 A\n",
+      "\n",
+      " Power delivered = 2116.00 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "R=10    #  ohm\n",
+    "Vs=230    #  V\n",
+    "f=1*1000    #  Hz\n",
+    "Ton=0.4    #  ms\n",
+    "k=0.4     #  duty cycle\n",
+    "\n",
+    "Vo=Vs*k    # V\n",
+    "Ioav=Vo/R    #  A\n",
+    "Vor=Vs*sqrt(k)    #  V\n",
+    "Po=Vor**2/R    #  W\n",
+    "print '\\n Average load current = %.1f A'%( Ioav)\n",
+    "print '\\n Power delivered = %.2f W'%(Po)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 5.2 page 185"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " duty ratio = 0.667\n",
+      "\n",
+      " chopping frequency = 33.33 Hz\n",
+      "\n",
+      " Average load voltage = 200.00 V\n",
+      "\n",
+      " Average load current = 40.00 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "\n",
+    "R=5    #  ohm\n",
+    "Vs=300    #  V\n",
+    "f=1*1000    #  Hz\n",
+    "Ton=20    #  ms\n",
+    "Toff=10    #  ms\n",
+    "\n",
+    "k= Ton/(Ton+Toff)    #  duty ratio\n",
+    "f=1000/(Ton+Toff)    # Hz\n",
+    "Voav=Vs*k    #  V\n",
+    "Ioav=Voav/R    #  A\n",
+    "print '\\n duty ratio = %.3f'%(k)\n",
+    "print '\\n chopping frequency = %.2f Hz'%(f)\n",
+    "print '\\n Average load voltage = %.2f V'%( Voav)\n",
+    "print '\\n Average load current = %.2f A'%( Ioav)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 5.3 page 185"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " chopping frequency = 15 Hz\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "\n",
+    "Vs=400    # V\n",
+    "alfa=0.25    #  duty cycle\n",
+    "delta_I=10    #  A\n",
+    "L=0.5    #  H\n",
+    "R=0    #  ohm\n",
+    "\n",
+    "Vo=alfa*Vs    # V\n",
+    "#Vo+L*di/dt=Vs -- putting dt=Ton & di=delta_I\n",
+    "Ton=delta_I/((Vs-Vo)/L)*1000    #  ms\n",
+    "T=Ton/alfa    #  ms\n",
+    "f=1/T*1000    # Hz\n",
+    "print '\\n chopping frequency = %d Hz'%(f)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 5.5 page 186"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Pulse width of output voltage, Ton = 200 us & T = 300 us\n",
+      "\n",
+      "New output voltage = 330 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt\n",
+    "\n",
+    "Vs=220    # V\n",
+    "Vo=660    #  V\n",
+    "Toff=100    #  us\n",
+    "\n",
+    "#Vo=Vs/(1-alfa)\n",
+    "alfa=1-Vs/Vo    #  duty cycle\n",
+    "#alfa=Ton/(Ton+Toff)\n",
+    "Ton=alfa*Toff/(1-alfa)    #  us\n",
+    "T=Ton+Toff    # us\n",
+    "print 'Pulse width of output voltage, Ton = %d us & T = %d us'%(Ton,T)\n",
+    "#(ii) reduce pulse width by 50%\n",
+    "Ton=Ton/2    #  us\n",
+    "Toff=T-Ton    #  us\n",
+    "alfa=Ton/(Ton+Toff)    #  duty cycle\n",
+    "Vo=Vs/(1-alfa)    #  V\n",
+    "print '\\nNew output voltage = %d V'%(Vo)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter7.ipynb b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter7.ipynb
new file mode 100644
index 00000000..eb5ab53f
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/chapter7.ipynb
@@ -0,0 +1,186 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 7 - Power Controllers - Their Applications"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 7.1 page 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " Speed of motor = 517 rpm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,cos,pi\n",
+    "N1=1000    #  rpm\n",
+    "Va1=200    #  V\n",
+    "alfa=60    #  degree\n",
+    "Va2=230    #  V\n",
+    "\n",
+    "N2=2*Va2*sqrt(2)*cos(alfa*pi/180)*N1/Va1/pi\n",
+    "print '\\n Speed of motor = %d rpm'%(N2)\n",
+    "# ans in the textbook is not accurate."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 7.2 page 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " duty ratio = 0.82\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "\n",
+    "N1=1100    #  rpm\n",
+    "Va1=220    #  V\n",
+    "N2=900    #  rpm\n",
+    "\n",
+    "Va2=Va1*N2/N1    #  V\n",
+    "delta=Va2/Va1    #  duty ratio\n",
+    "print '\\n duty ratio = %.2f'%(delta)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 7.3 page 261"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " triggering angle = 57.9 degree\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import sqrt,cos,pi,acos\n",
+    "\n",
+    "N1=900    #  rpm\n",
+    "Va1=198    #  V\n",
+    "N2=500    #  rpm\n",
+    "Vs=230    #  V\n",
+    "\n",
+    "Va2=Va1*N2/N1    #  V\n",
+    "# 2*sqrt(2)*Vs*cos(alfa)/pi=Va2\n",
+    "alfa=acos(Va2/(2*sqrt(2)*Vs)*pi)*180/pi    #  degree\n",
+    "\n",
+    "print '\\n triggering angle = %.1f degree'%(alfa)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Ex 7.4 page 261"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      " average armature current = 9.35 A\n",
+      "\n",
+      " torque = 4.674 Nm\n"
+     ]
+    }
+   ],
+   "source": [
+    "from __future__ import division\n",
+    "from math import pi\n",
+    "Vs=230    #  V\n",
+    "Ton=10    #  ms\n",
+    "Toff=25    #  ms\n",
+    "Ra=2    # ohm\n",
+    "N=1400    #  rpm\n",
+    "k=0.5    #  V/rad/s (back emf constant)\n",
+    "kt=0.5    #  NM-A**-1 (torque constant)\n",
+    "\n",
+    "Eb=N*2*pi*k/60    #  V\n",
+    "Va=Vs*Ton/(Toff)    #  V\n",
+    "Ia=(Va-Eb)/Ra    #  A\n",
+    "T=kt*Ia    #  Nm\n",
+    "print '\\n average armature current = %.2f A'%( Ia)\n",
+    "print '\\n torque = %.3f Nm'%( T)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/avgArmCurr7_.png b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/avgArmCurr7_.png
new file mode 100644
index 00000000..5620405b
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/avgArmCurr7_.png
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/speedmotor7.png b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/speedmotor7.png
new file mode 100644
index 00000000..482bd324
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/speedmotor7.png
diff --git a/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/triggeringangle7.png b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/triggeringangle7.png
new file mode 100644
index 00000000..8fe09343
--- /dev/null
+++ b/Introduction_to_Power_Electronics_by_V._Jagannathan/screenshots/triggeringangle7.png
diff --git a/sample_notebooks/ArchanaDharmasagar Kalidas/Chapter1.ipynb b/sample_notebooks/ArchanaDharmasagar Kalidas/Chapter1.ipynb
new file mode 100644
index 00000000..55a10563
--- /dev/null
+++ b/sample_notebooks/ArchanaDharmasagar Kalidas/Chapter1.ipynb
@@ -0,0 +1,568 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 1: Atomic Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 55"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of emitted photon is 1.281 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=3;\n",
+    "n2=5;        #states\n",
+    "RH=1.0977*10**7;\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=RH*((1/n1**2)-(1/n2**2));\n",
+    "lamda=10**6/newbar;         #wavelength of emitted photon(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of emitted photon is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of principal quantum number of two orbits is 14 / 11\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "E1=1.21;\n",
+    "E2=1.96;        #energy of two orbits(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n1=math.sqrt(E2);\n",
+    "n2=math.sqrt(E1);       #ratio of principal quantum number of two orbits\n",
+    "n1=n1*10;\n",
+    "n2=n2*10;               #multiply and divide the ratio by 10\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of principal quantum number of two orbits is\",int(n1),\"/\",int(n2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment of proton is 5.041 *10**-27 Am**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "mp=1.672*10**-27;         #mass of electron(kg)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewp=e*h/(4*math.pi*mp);  #magnetic moment of proton(Am**2) \n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment of proton is\",round(mewp*10**27,3),\"*10**-27 Am**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "specific charge of electron is 1.7604 *10**11 coulomb/kg\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "mewB=9.274*10**-24;       #bohr magneton(amp m**2)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "ebym=mewB*4*math.pi/h;    #specific charge of electron(coulomb/kg)      \n",
+    "\n",
+    "#Result\n",
+    "print \"specific charge of electron is\",round(ebym/10**11,4),\"*10**11 coulomb/kg\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength separation is 0.3358 angstrom\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "B=1;                #flux density(Wb/m**2)\n",
+    "lamda=6000*10**-10; #wavelength(m)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "c=3*10**8;          #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "d_lamda=B*e*(lamda**2)/(4*math.pi*m*c);     #wavelength separation(m)\n",
+    "d_lamda=2*d_lamda*10**10;                   #wavelength separation(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength separation is\",round(d_lamda,4),\"angstrom\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of electron in 1st and 2nd orbit is -13.6 eV and -3.4 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        #states\n",
+    "\n",
+    "#Calculations\n",
+    "E1=-13.6/n1**2;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-13.6/n2**2;     #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of electron in 1st and 2nd orbit is\",E1,\"eV and\",E2,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "linear momentum is 2.107 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "lamda=0.5*10**-10;        #radius of 1st orbit(m)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "L=h/(2*math.pi*lamda);    #linear momentum(kg ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"linear momentum is\",round(L*10**24,3),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "state to which it is excited is 4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "E1=-13.6;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-12.75;    #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n=math.sqrt(-E1/(E2-E1));    #state to which it is excited\n",
+    "\n",
+    "#Result\n",
+    "print \"state to which it is excited is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "bohr magneton is 9.262 *10**-24 coulomb Js kg-1\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "h=6.62*10**-34;         #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewB=e*h/(4*math.pi*m);  #bohr magneton(coulomb Js kg-1) \n",
+    "\n",
+    "#Result\n",
+    "print \"bohr magneton is\",round(mewB*10**24,3),\"*10**-24 coulomb Js kg-1\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "component separation is 2.7983 *10**8 Hz\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "B=0.02;                 #magnetic field(T)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=e*B/(4*math.pi*m);    #component separation(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"component separation is\",round(delta_new/10**8,4),\"*10**8 Hz\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 61"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic flux density is 2.14 Tesla\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=10000*10**-10;    #wavelength(m)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "d_lamda=1*10**-10;      #wavelength separation(m)\n",
+    "\n",
+    "#Calculations\n",
+    "B=d_lamda*4*math.pi*m*c/(e*lamda**2);      #magnetic flux density(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic flux density is\",round(B,2),\"Tesla\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 19, Page number 66"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "separation is 0.33 angstrom\n",
+      "wavelength of three components is 4226 angstrom 4226.33 angstrom 4226.666 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=4226;             #wavelength(angstrom)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "B=4;                    #magnetic field(Wb/m**2)\n",
+    "\n",
+    "#Calculations\n",
+    "dnew=B*e/(4*math.pi*m);    \n",
+    "dlamda=lamda**2*dnew*10**-10/c;      #separation(angstrom)\n",
+    "dlamda1=lamda+dlamda;\n",
+    "dlamda2=dlamda1+dlamda;    #wavelength of three components(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"separation is\",round(dlamda,2),\"angstrom\"\n",
+    "print \"wavelength of three components is\",lamda,\"angstrom\",round(dlamda1,2),\"angstrom\",round(dlamda2,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 21, Page number 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of elements would be 110\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        \n",
+    "n3=3;\n",
+    "n4=4;\n",
+    "n5=5;\n",
+    "\n",
+    "#Calculations\n",
+    "e1=2*n1**2;     #maximum number of electrons in 1st orbit\n",
+    "e2=2*n2**2;     #maximum number of electrons in 2nd orbit\n",
+    "e3=2*n3**2;     #maximum number of electrons in 3rd orbit\n",
+    "e4=2*n4**2;     #maximum number of electrons in 4th orbit\n",
+    "e5=2*n5**2;     #maximum number of electrons in 5th orbit\n",
+    "e=e1+e2+e3+e4+e5;      #number of elements\n",
+    "\n",
+    "#Result\n",
+    "print \"number of elements would be\",e"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}