1 files changed, 177 insertions, 0 deletions
diff --git a/Engineering_Physics/chapter5.ipynb b/Engineering_Physics/chapter5.ipynb
new file mode 100755
index 00000000..bf9aee93
--- /dev/null
+++ b/Engineering_Physics/chapter5.ipynb
@@ -0,0 +1,177 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:141e2987b2be679ae1fc9e807cf81c12805438f836d3be09701fc88866bf9bb5"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter5:LASERS"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Ex5.1:pg-164"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math\n",
+      "#to calculate area of the spot on the moon\n",
+      "lamda=6*10**-7 #wavelength in m\n",
+      "d=2 #diameter in m\n",
+      "dtheta=lamda/d #angular spread in radian\n",
+      "D=4*10**8 #distance of the moon\n",
+      "A=(D*dtheta)**2\n",
+      "print \"the areal spread is A=\",\"{:.2e}\".format(A),\"m**2\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the areal spread is A= 1.44e+04 m**2\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Ex5.2:pg-164"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math\n",
+      "#to calculate angular spread of the beam\n",
+      "lamda=8*10**-7 #wavelength in m\n",
+      "d=5*10**-3 #aperture in m\n",
+      "dtheta=lamda/d \n",
+      "print \"the angular spread of the beam is dtheta=\",\"{:.1e}\".format(dtheta),\"radian\"\n",
+      "#to calculate the areal spread when it reaches the moon\n",
+      "D=4*10**8 #distance of the moon in m\n",
+      "A=(D*dtheta)**2\n",
+      "print \"the areal spread is A=\",\"{:.3e}\".format(A),\"m**2\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the angular spread of the beam is dtheta= 1.6e-04 radian\n",
+        "the areal spread is A= 4.096e+09 m**2\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Ex5.3:pg-165"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math\n",
+      "#to calculate number of oscillations corresponding to the coherence length\n",
+      "L=2.945*10**-2 #coherence length in m\n",
+      "lamda=5890*10**-10 #wavelength of sodium light in m\n",
+      "n=L/lamda\n",
+      "print \"the number of oscillations is n=\",\"{:.1e}\".format(n),\"unitless\"\n",
+      "#to calculate coherence time\n",
+      "c=3*10**8 #light speed in m\n",
+      "Time=L/c #coherence time\n",
+      "print \"the coherence Time=\",\"{:.2e}\".format(Time),\"s\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the number of oscillations is n= 5.0e+04 unitless\n",
+        "the coherence Time= 9.82e-11 s\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Ex5.4:pg-165"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math\n",
+      "#to calculate area and intensity of the image\n",
+      "lamda=7200*10**-10 #wavelength in m\n",
+      "d=5*10**-3 #aperture in m\n",
+      "dtheta=lamda/d #angular spread in radian \n",
+      "f=0.1 #focal length in m\n",
+      "arealspread=(dtheta*f)**2\n",
+      "print \"areal spread =\",\"{:.3e}\".format(arealspread),\"m**2\"\n",
+      "power=50*10**-3\n",
+      "I=power/arealspread\n",
+      "print \"intensity of the image is I=\",\"{:.3e}\".format(I),\"watts/m**2\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "areal spread = 2.074e-10 m**2\n",
+        "intensity of the image is I= 2.411e+08 watts/m**2\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
+\ No newline at end of file