From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001
From: priyanka
Date: Wed, 24 Jun 2015 15:03:17 +0530
Subject: initial commit / add all books

---
 2642/CH5/EX5.7/Ex5_7.sce | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100755 2642/CH5/EX5.7/Ex5_7.sce

(limited to '2642/CH5/EX5.7')

diff --git a/2642/CH5/EX5.7/Ex5_7.sce b/2642/CH5/EX5.7/Ex5_7.sce
new file mode 100755
index 000000000..053bc52fb
--- /dev/null
+++ b/2642/CH5/EX5.7/Ex5_7.sce
@@ -0,0 +1,31 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES 
+// M.A.SALAM 
+// NAROSA PUBLISHING HOUSE 
+// SECOND EDITION
+
+// Chapter 5 : DIRECT CURRENT MOTORS
+// Example : 5.7
+
+clc;clear; // clears the console and command history 
+
+// Given data
+I_a1 = 65     // supply current to dc series motor in A
+V_t = 230     // supply voltage in V
+N_1 = 900     // speed in rpm
+R_a = 0.2     // armature resistance in ohm
+R_sh = 0.25   // field resistance in ohm
+I_a2 = 15     // supply current to dc series motor in A
+// phi_2 = 0.4*phi_1 value of flux
+
+
+// caclulations 
+E_b1 = V_t-I_a1*(R_a+R_sh)     // initial back emf in V
+E_b2 = V_t-I_a2*(R_a+R_sh)     // final back emf in V
+// phi_2 = 0.4*phi_1 value of flux
+N_2 = (E_b2/E_b1)*(2.5)*N_1    // motor speed when line current is 15A in rpm
+
+// display the result 
+disp("Example 5.7 solution");
+printf(" \n motor speed when line current is 15A \n N_2 = %.0f rpm \n", N_2 );
+
+printf(" NOTE: in question they given I_a1=56A , but in solution they took I_a1=65A");
-- 
cgit