adding books

17 files changed, 1968 insertions, 0 deletions

diff --git a/Engineering_Physics/Chapter1.ipynb b/Engineering_Physics/Chapter1.ipynb
new file mode 100755
index 00000000..a3614569
--- /dev/null
+++ b/Engineering_Physics/Chapter1.ipynb
@@ -0,0 +1,357 @@
+{
+ "metadata": {
+  "name": "Chapter1",
+  "signature": "sha256:e55f587b2da98ead68f73bb2b4d29bef91aa67eb577c460fb9dcaab92acc4339"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "1: Ultrasonics"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.1, Page number 20"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#Variable declaration\nv = 1440;         #velocity of ultrasonic waves(m/s)\nt = 0.33;         #time elapsed(s)\n\n#Calculation\nd = v*t;      #distance travelled(m)\nd1 = d/2;     #depth of submarine(m)\n\n#Result\nprint \"depth of the submerged submarine is\",d1, \"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 237.6 m\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.2, Page number 21"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 40;     #length of iron rod(mm)\nE = 115*10**9;      #Young's modulus(N/m**2)\nrho = 7.25*10**3;   #density of pure iron(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-3;             #natural frequency of the rod(kHz)\nnew=math.ceil(new*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"depth of the submerged submarine is\",new, \"kHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 49.785 kHz\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.3, Page number 21"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 1;     #length of quartz crystal(mm)\nE = 7.9*10**10;      #Young's modulus(N/m**2)\nrho = 2650;   #density(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-6;                   \nnew=math.ceil(new*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"fundamental frequency of crystal is\",new, \"*10**6 Hz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "fundamental frequency of crystal is 2.73 *10**6 Hz\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.4, Page number 22"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nd = 0.55;        #distance between 2 constructive antinodes(mm)\nnew = 1.5;      #frequency of crystal(MHz)\n \n#Calculation\nnew = new*10**6;        #frequency of crystal(Hz)\nd = d*10**-3;     #distance between 2 constructive antinodes(m)\n#distance between 2 antinodes is given by lamda/2\nlamda = 2*d;      #wavelength of ultrasonic waves(m)\nv = new*lamda;       #velocity of waves(m/s)\n\n#Result\nprint \"velocity of waves is\",int(v), \"m/s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "velocity of waves is 1650 m/s\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.5, Page number 22"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 50;     #length of rod(mm)\nE = 11.5*10**10;      #Young's modulus(N/m**2)\nrho = 7250;   #density(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-3;       #natural frequency of the rod(kHz)\nnew = math.ceil(new*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"natural frequency of rod is\",new, \"kHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "natural frequency of rod is 39.83 kHz\n"
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.6, Page number 22"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 2;     #length of crystal(mm)\nE = 7.9*10**10;      #Young's modulus(N/m**2)\nrho = 2650;   #density(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-6;         #natural frequency of the rod(MHz)\nnew=math.ceil(new*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"frequency of crystal is\",new, \"MHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "frequency of crystal is 1.365 MHz\n"
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.7, Page number 23"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 3;     #length of crystal(mm)\nE = 8*10**10;      #Young's modulus(N/m**2)\nrho = 2500;   #density(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-3;         #natural frequency of the rod(kHz) \nnew=math.ceil(new*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"frequency of crystal is\",new, \"kHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "frequency of crystal is 942.81 kHz\n"
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.8, Page number 23"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 1.5;     #length of crystal(mm)\nE = 7.9*10**10;      #Young's modulus(N/m**2)\nrho = 2650;   #density(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-6;         #natural frequency of the rod(MHz) \nnew=math.ceil(new*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"frequency of crystal is\",new, \"MHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "frequency of crystal is 1.82 MHz\n"
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.9, Page number 24"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#Variable declaration\nv = 1440;         #velocity of ultrasonic waves(m/s)\nt = 0.95;         #time elapsed(s)\n\n#Calculation\nd = v*t;      #distance travelled(m)\nd1 = d/2;     #depth of sea(m)\n\n#Result\nprint \"depth of the submerged submarine is\",int(d1), \"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 684 m\n"
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.10, Page number 24"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#Variable declaration\nv = 1440;         #velocity of ultrasonic waves(m/s)\nt = 0.83;         #time elapsed(s)\n\n#Calculation\nd = v*t;      #distance travelled(m)\nd1 = d/2;     #depth of submarine(m)\n\n#Result\nprint \"depth of the submerged submarine is\",d1, \"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 597.6 m\n"
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.11, Page number 24"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\naS = 1050;      #total absorption inside hall(Sabine)\nV = 9000;       #volume of cinema hall(m**3)\n\n#Calculation\nT = 0.165*V/aS;     #reverberation time of hall(s)\nT = math.ceil(T*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"reverberation time of the hall is\",T, \"s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "reverberation time of the hall is 1.4143 s\n"
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.12, Page number 25"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\na = 0.65;      #average absorption coefficient(Sabine/m**2)\nV = 13500;       #volume of auditorium(m**3)\nT = 1.2;         #reverberation time of hall(s)\n\n#Calculation\nS = 0.165*V/(a*T);     #reverberation time of hall(s)\nS = math.ceil(S*10)/10;   #rounding off to 1 decimal\n\n#Result\nprint \"total area of interior surface is\",S, \"m**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "total area of interior surface is 2855.8 m**2\n"
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.13, Page number 25"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nV = 15000;       #volume of cinema hall(m**3)\nT1 = 1.3;        #initial reverberation time of hall(s)\na1S1 = 300;      #number of chairs placed\n\n#Calculation\naS = 0.165*V/T1;         #total absorption of hall\nT2 = (0.165*V)/(aS+a1S1);      #reverberation time of hall after adding chairs(s)\nT2 = math.ceil(T2*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"reverberation time of the hall after adding chairs is\",T2, \"s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "reverberation time of the hall after adding chairs is 1.1231 s\n"
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.14, Page number 26"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#Variable declaration\nv = 1440;         #velocity of ultrasonic waves(m/s)\nt = 0.5;         #time elapsed(s)\n\n#Calculation\nd = v*t;      #distance travelled(m)\nd1 = d/2;     #depth of submarine(m)\n\n#Result\nprint \"depth of the submerged submarine is\",int(d1), \"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 360 m\n"
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.15, Page number 26"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nd = 0.4;        #distance between 2 constructive antinodes(mm)\nnew = 1.5;      #frequency of crystal(MHz)\n \n#Calculation\nnew = new*10**6;        #frequency of crystal(Hz)\nd = d*10**-3;     #distance between 2 constructive antinodes(m)\n#distance between 2 antinodes is given by lamda/2\nlamda = 2*d;      #wavelength of ultrasonic waves(m)\nv = new*lamda;       #velocity of waves(m/s)\n\n#Result\nprint \"velocity of waves is\",int(v), \"m/s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "velocity of waves is 1200 m/s\n"
+      }
+     ],
+     "prompt_number": 17
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 1.16, Page number 26"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nl = 40;     #length of iron rod(mm)\nE = 11.5*10**10;      #Young's modulus(N/m**2)\nrho = 7250;   #density of pure iron(kg/m**3)\n\n#Calculation\nl = l*10**-3;     #length of iron rod(m)\nnew = (1/(2*l))*math.sqrt(E/rho);     #natural frequency of the rod(Hz)\nnew = new*10**-3;             #natural frequency of the rod(kHz)\nnew=math.ceil(new*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"depth of the submerged submarine is\",new, \"kHz\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "depth of the submerged submarine is 49.785 kHz\n"
+      }
+     ],
+     "prompt_number": 18
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter10.ipynb b/Engineering_Physics/Chapter10.ipynb
new file mode 100755
index 00000000..051ee9c1
--- /dev/null
+++ b/Engineering_Physics/Chapter10.ipynb
@@ -0,0 +1,62 @@
+{
+ "metadata": {
+  "name": "Chapter10"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "10: Dielectric Materials"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 10.1, Page number 289"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nepsilon_r = 1.0000684;            #dielectric constant\nN = 2.7*10**25;                   #number of atoms(per m**3)\nepsilon0 = 8.85*10**-12;          #permittivity of free space\n\n#Calculation\nalpha_e = epsilon0*(epsilon_r-1)/N;       #electronic polarizability(Fm**2)\n\n#Result\nprint \"electronic polarizability is\",alpha_e,\"Fm**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electronic polarizability is 2.242e-41 Fm**2\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 10.2, Page number 290"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nepsilon_r = 1.0024;            #relative permittivity\nN = 2.7*10**25;                   #number of atoms(per m**3)\nepsilon0 = 8.85*10**-12;          #permittivity of free space\n\n#Calculation\nalpha_e = epsilon0*(epsilon_r-1)/N;       #electronic polarizability(Fm**2)\n\n#Result\nprint \"electronic polarizability is\",alpha_e,\"Fm**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electronic polarizability is 7.86666666667e-40 Fm**2\n"
+      }
+     ],
+     "prompt_number": 2
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter2.ipynb b/Engineering_Physics/Chapter2.ipynb
new file mode 100755
index 00000000..fff10b22
--- /dev/null
+++ b/Engineering_Physics/Chapter2.ipynb
@@ -0,0 +1,84 @@
+{
+ "metadata": {
+  "name": "Chapter2",
+  "signature": "sha256:ac80f9dfe1725f11a5d4ce0fbda5ffed825d99c680f116629e5e3fcb8b69c198"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "2: Lasers"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 2.1, Page number 52"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nlamda = 590;        #wavelength(nm)\nh = 6.625*10**-34;       #planck's constant\nc = 3*10**8;            #velocity of light(m/s)\nk = 1.38*10**-23;       #boltzmann's constant\nT = 523;                #temperature(Kelvin)\n\n#Calculation\nlamda = lamda*10**-9;      #wavelength(m)      \n#n1byn2 = math.exp(-(E2-E1)/(k*T))\n#but E2-E1 = h*new and new = c/lamda\n#therefore n1byn2 = math.exp(-h*c/(lamda*k*T))\nn1byn2 = math.exp(-h*c/(lamda*k*T));\n\n#Result\nprint \"relative population of Na atoms is\",n1byn2",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "relative population of Na atoms is 5.36748316686e-21\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 2.2, Page number 53"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nlamda = 590;        #wavelength(nm)\nh = 6.625*10**-34;       #planck's constant\nc = 3*10**8;            #velocity of light(m/s)\nk = 1.38*10**-23;       #boltzmann's constant\nT = 523;                #temperature(Kelvin)\n\n#Calculation\nlamda = lamda*10**-9;      #wavelength(m)      \n#n21dashbyn21 = 1/(math.exp(h*new/(k*T))-1)\n#but new = c/lamda\n#therefore n21dashbyn21 = 1/(math.exp(h*c/(lamda*k*T))-1)\nA = math.exp(h*c/(lamda*k*T))-1;\nn21dashbyn21 = 1/A;    \n\n#Result\nprint \"ratio of stimulated to spontaneous emission is\",n21dashbyn21\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "ratio of stimulated to spontaneous emission is 5.36748316686e-21\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 2.3, Page number 53"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nlamda = 632.8;        #wavelength of laser(nm)\nh = 6.625*10**-34;       #planck's constant\nc = 3*10**8;            #velocity of light(m/s)\np = 3.147;              #output power(mW)\n\n#Calculation\np = p*10**-3;          #output power(W)\nlamda = lamda*10**-9;      #wavelength(m)      \nnew = c/lamda;             #frequency(Hz)\nE = h*new;                 #energy of each photon(J)\nEm = p*60;                 #energy emitted per minute(J/min)\nN = Em/E;                  #number of photons emitted per second\n\n#Result\nprint \"number of photons emitted per second is\",N",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "number of photons emitted per second is 6.01183879245e+17\n"
+      }
+     ],
+     "prompt_number": 3
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter3.ipynb b/Engineering_Physics/Chapter3.ipynb
new file mode 100755
index 00000000..9e2d3109
--- /dev/null
+++ b/Engineering_Physics/Chapter3.ipynb
@@ -0,0 +1,83 @@
+{
+ "metadata": {
+  "name": "Chapter3"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "3: Fibre Optics and Applications"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 3.1, Page number 84"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn1 = 1.5;          #refractive index of core\nn2 = 1.47;         #refractive index of cladding\nn0 = 1;            #refractive index of air\na = 180/math.pi;        #conversion factor of radian to degree\n\n#Calculation\nNA = math.sqrt((n1**2)-(n2**2));     #numerical aperture\nNA=math.ceil(NA*10)/10;   #rounding off to 1 decimal\nalpha_m = math.asin(NA/n0);         #acceptance angle(radian)\nalpha_m = alpha_m*a;                #acceptance angle(degrees)\nalpha_m=math.ceil(alpha_m*10**2)/10**2;   #rounding off to 2 decimals\nphi_m = math.asin(NA/n1);           #phase angle(radian)\nphi_m = phi_m*a;                    #phase angle(degrees)\nphi_m=math.ceil(phi_m*10**2)/10**2;   #rounding off to 2 decimals\ntheta_c = math.asin(n2/n1);         #critical angle(radian)\ntheta_c = theta_c*a;                #critical angle(degrees)\ntheta_c=math.ceil(theta_c*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"numerical aperture is\",NA\nprint \"acceptance angle is\",alpha_m,\"degrees\"\nprint \"phase angle is\",phi_m,\"degrees\"\nprint \"critical angle is\",theta_c,\"degrees\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "numerical aperture is 0.3\nacceptance angle is 17.46 degrees\nphase angle is 11.54 degrees\ncritical angle is 78.522 degrees\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 3.2, Page number 85"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn1 = 1.5;          #refractive index of core\nn2 = 1.47;         #refractive index of cladding\nc = 3*10**8;       #velocity of light(m/sec)\n\n#Calculation\ndeltatbyL = (n1/n2)*((n1-n2)/c);\n\n#Result\nprint \"pulse broadening per unit length is\",deltatbyL,\"s/m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "pulse broadening per unit length is 1.02040816327e-10 s/m\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 3.3, Page number 85"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nphi_m = 11.54;       #phase angle(degrees)\na = 0.5*10**-4;\nx = math.pi/180;       #conversion factor from degrees to radians\n\n#Calculation\nphi_m = phi_m*x;      #phase angle(radian)\nL = a/math.tan(phi_m);      #length(m)\nn = 1/(2*L);          #total number of internal reflections(m-1)\n\n#Result\nprint \"alpha = 0 rays have no reflection. hence there are zero reflections for 1 metre.\"\nprint \"alpha = alpha_m rays have\",int(n),\"m-1 internal reflections\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "alpha = 0 rays have no reflection. hence there are zero reflections for 1 metre.\nalpha = alpha_m rays have 2041 m-1 internal reflections\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 7
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter4.ipynb b/Engineering_Physics/Chapter4.ipynb
new file mode 100755
index 00000000..5651b165
--- /dev/null
+++ b/Engineering_Physics/Chapter4.ipynb
@@ -0,0 +1,209 @@
+{
+ "metadata": {
+  "name": "Chapter4"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "4: Quantum Physics"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.1, Page number 117"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nc = 3*10**8;       #velocity of light(m/sec)\nh = 6.62*10**-34;     #planck's constant\nlamda = 1.2;          #wavelength of photon(Angstrom)\ne = 1.6*10**-19;      #conversion factor from J to eV\n\n#Calculation\nlamda = lamda*10**-10;       #wavelength of photon(m)\nE = (h*c)/(lamda*e);         #energy of photon(eV)\nE=math.ceil(E*10)/10;   #rounding off to 1 decimal\np = h/lamda;            #momentum of photon(kg m/s)\n\n#Result\nprint \"energy of the photon is\",E,\"eV\"\nprint \"momentum of the photon is\",p,\"kg m/s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "energy of the photon is 10343.8 eV\nmomentum of the photon is 5.51666666667e-24 kg m/s\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.2, Page number 117"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nh = 6.625*10**-34;     #planck's constant\nnew = 900;             #frequency(kHz)\nE1 = 10;               #power radiated(kW)\n\n#Calculation\nE1 = E1*10**3;         #power radiated(W)\nnew = new*10**3;       #frequency(Hz)\nE = h*new;         #energy of photon(J)\nN = E1/E;          #number of photons emitted \n\n#Result\nprint \"number of photons emitted per second is\",N",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "number of photons emitted per second is 1.67714884696e+31\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.3, Page number 118"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nc = 3*10**8;       #velocity of light(m/sec)\nh = 6.63*10**-34;     #planck's constant\nlamda = 5893;         #wavelength of photon(Angstrom)\nE1 = 100;             #power of lamp(W) \n\n#Calculation\nlamda = lamda*10**-10;       #wavelength of photon(m)\nE = h*c/lamda;         #energy of photon(J)\nN = E1/E;          #number of photons emitted \n\n#Result\nprint \"number of photons emitted per second is\",N\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "number of photons emitted per second is 2.96279537456e+20\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.4, Page number 118"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nc = 3*10**8;       #velocity of light(m/sec)\nh = 6.6*10**-34;     #planck's constant\nm0 = 9.1*10**-31;        #mass of photon(kg)\ntheta = 30;              #viewing angle(degrees)\nlamda = 2.8*10**-10;         #wavelength of photon(m)\n\n#Calculation\nx = math.pi/180;       #conversion factor from degrees to radians\ntheta = theta*x;       #viewing angle(radian) \nlamda_dash = (2*h*(math.sin(theta/2))**2/(m0*c))+lamda;        #wavelength of scattered radiation(m)\nlamda_dash = lamda_dash*10**10;           #wavelength of scattered radiation(Angstrom)\nlamda_dash=math.ceil(lamda_dash*10**5)/10**5;   #rounding off to 5 decimals\n\n#Result\nprint \"wavelength of scattered radiation is\",lamda_dash,\"Angstrom\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "wavelength of scattered radiation is 2.80324 Angstrom\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.5, Page number 119"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nh = 6.6*10**-34;     #planck's constant\nm = 0.040;        #mass of bullet(kg)\nv = 1;            #speed of bullet(km/s)\n\n#Calculation\nv = v*10**3;      #speed of bullet(m/s)\np = m*v;          #momemtun of bullet(kg m/s)\nlamda = h/p;      #deBroglie wavelength(m)\nlamda = lamda*10**10;     #deBroglie wavelength(Angstrom)\n\n#Result\nprint \"deBroglie wavelength is\",lamda,\"Angstrom\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "deBroglie wavelength is 1.65e-25 Angstrom\n"
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.6, Page number 119"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn = 1;               #lowest energy state\na = 0.1;             #width of box(nm)\nh = 6.625*10**-34;     #planck's constant\ne = 1.602*10**-19;       #conversion factor from J to eV\nm = 9.11*10**-31;        #mass of particle(kg)\n\n#Calculation\na = a*10**-9;        #width of box(m)\nE = (n**2)*(h**2)/(8*m*(a**2));      #energy of particle(J)\nE_eV = E/e;             #energy of particle(eV)\nE_eV=math.ceil(E_eV*10)/10;   #rounding off to 1 decimal\n\n#Result\nprint \"energy of particle is\",E,\"J or\",E_eV,\"eV\" ",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "energy of particle is 6.02231407794e-18 J or 37.6 eV\n"
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.7, Page number 120"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn = 1;               #lowest energy state\na = 4;             #width of well(nm)\nh = 6.625*10**-34;     #planck's constant\ne = 1.6025*10**-19;       #conversion factor from J to eV\nm = 9.11*10**-31;        #mass of electron(kg)\n\n#Calculation\na = a*10**-9;        #width of box(m)\nE = (n**2)*(h**2)/(8*m*(a**2));      #energy of particle(J)\nE_eV = E/e;             #energy of particle(eV)\nE_eV=math.ceil(E_eV*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"minimum energy of electron is\",E,\"J or\",E_eV,\"eV\" ",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "minimum energy of electron is 3.76394629871e-21 J or 0.0235 eV\n"
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.8, Page number 120"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn1 = 1;               #lowest energy state\nn2 = 6;               #for 6th excited state\na = 0.1;             #width of box(nm)\nh = 6.625*10**-34;     #planck's constant\ne = 1.602*10**-19;       #conversion factor from J to eV\nm = 9.11*10**-31;        #mass of electron(kg)\n\n#Calculation\na = a*10**-9;        #width of box(m)\nE1 = (n1**2)*(h**2)/(8*m*(a**2));      #energy of electron in ground state(J)\nE6 = (n2**2)*(h**2)/(8*m*(a**2));      #energy of electron in excited state(J)\nE = E6-E1;                          #energy required to excite the electron(J)\nE_eV = E/e;             #energy required to excite the electron(eV)\nE_eV=math.ceil(E_eV*10)/10;   #rounding off to 1 decimal\n\n#Result\nprint \"energy required to excite the electron is\",E,\"J or\",E_eV,\"eV\" \nprint \"answer for energy in eV given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "energy required to excite the electron is 2.10780992728e-16 J or 1315.8 eV\nanswer for energy in eV given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 4.9, Page number 121"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nh = 6.625*10**-34;     #planck's constant\nc = 3*10**8;       #velocity of light(m/sec)\nm0 = 9.11*10**-31;        #rest mass of electron(kg)\nphi = 90;              #angle of scattering(degrees)\nx = math.pi/180;       #conversion factor from degrees to radians\n\n#Calculation\nphi = phi*x;           ##angle of scattering(radian)\ndelta_lamda = h*(1-math.cos(phi))/(m0*c);         #change in wavelength(m)\n\n#Result\nprint \"change in wavelength of X-ray photon is\",delta_lamda,\"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "change in wavelength of X-ray photon is 2.42407610684e-12 m\n"
+      }
+     ],
+     "prompt_number": 9
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter5.ipynb b/Engineering_Physics/Chapter5.ipynb
new file mode 100755
index 00000000..ba6e0e69
--- /dev/null
+++ b/Engineering_Physics/Chapter5.ipynb
@@ -0,0 +1,152 @@
+{
+ "metadata": {
+  "name": "Chapter5"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "5: Crystal Physics"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.1, Page number 149, theoretical"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.2, Page number 150"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn = 8;          #number of atoms per cell\na = 5.43*10**-8;       #lattice constant(cm)\nw = 28.1;              #atomic weight(gm)\nN = 6.02*10**23;       #avagadro number\n\n#Calculation\nac = n/(a**3);         #atomic concentration(atoms/cm**3)\nd = ac*w/N;            #density of Si(g/cm**3)\nd=math.ceil(d*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"density of Si is\",d,\"g/cm**3\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "density of Si is 2.333 g/cm**3\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.3, Page number 151"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\na = 5;       #lattice constant(Angstrom)\n\n#Calculation\na = a*10**-10;         #lattice constant(m)\n#to calculate the planar concentration, only equilateral triangular region is considered of length a*math.sqrt(2) and height a*math.sqrt(3/2)\nl = a*math.sqrt(2);           #length of face diagonal(m)\nh = a*math.sqrt(3/2);         #height of triangle(m)\nA = l*h/2;                    #area of shaded portion(m**2)\n#every atom at the corner contributes 1/6 to this area.\nn111 = (3/6)*(1/A);           #planar concentration(atoms/m**2)\n\n#Result\nprint \"surface density of atoms is\",n111,\"atoms/m**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "surface density of atoms is 2.30940107676e+18 atoms/m**2\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.4, Page number 152"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\na = 4.049;       #lattice constant(Angstrom)\nh = 2;\nk = 2;\nl = 0;           #miller indices of(2 2 0)\n\n#Calculation\nd = a/math.sqrt(h**2+k**2+l**2);        #spacing of planes(Angstrom)\nd=math.ceil(d*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"spacing of planes is\",d,\"Angstrom\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "spacing of planes is 1.432 Angstrom\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.5, Page number 152"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nd110 = 2.03;       #distance between planes(Angstrom)\nh = 1;\nk = 1;\nl = 0;           #miller indices of(1 1 0)\n\n#Calculation\na = d110*math.sqrt(h**2+k**2+l**2);        #size of unit cell(Angstrom)\na=math.ceil(a*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"size of unit cell is\",a,\"Angstrom\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "size of unit cell is 2.871 Angstrom\n"
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.6, Page number 152"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\na = 5.64;       #lattice constant(Angstrom)\nh1 = 1;\nk1 = 0;\nl1 = 0;           #miller indices of(1 0 0)\nh2 = 1;\nk2 = 1;\nl2 = 0;           #miller indices of(1 1 0)\nh3 = 1;\nk3 = 1;\nl3 = 1;           #miller indices of(1 1 1)\n\n#Calculation\nd100 = a/math.sqrt(h1**2+k1**2+l1**2);        #spacing of planes[100](Angstrom)\nd110 = a/math.sqrt(h2**2+k2**2+l2**2);        #spacing of planes[110](Angstrom)\nd111 = a/math.sqrt(h3**2+k3**2+l3**2);        #spacing of planes[111](Angstrom)\nd111=math.ceil(d111*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"spacing of plane [100] is\",d100,\"Angstrom\"\nprint \"spacing of plane [110] is\",round(d110),\"Angstrom\"\nprint \"spacing of plane [111] is\",d111,\"Angstrom\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "spacing of plane [100] is 5.64 Angstrom\nspacing of plane [110] is 4.0 Angstrom\nspacing of plane [111] is 3.26 Angstrom\n"
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 5.7, Page number 153"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nr = 1.605;         #radius of atom(Angstrom)\n\n\n#Calculation\nr = r*10**-10;      #radius of atom(m)\na = 2*r;        #size of unit cell(m)\nc = a*math.sqrt(8/3);\nV = 3*math.sqrt(3)*a**2*c/2;       #volume of unit cell(m**3)\n\n#Result\nprint \"volume of unit cell is\",V,\"m**3\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "volume of unit cell is 1.40330266432e-28 m**3\n"
+      }
+     ],
+     "prompt_number": 7
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter6.ipynb b/Engineering_Physics/Chapter6.ipynb
new file mode 100755
index 00000000..768ed817
--- /dev/null
+++ b/Engineering_Physics/Chapter6.ipynb
@@ -0,0 +1,356 @@
+{
+ "metadata": {
+  "name": "Chapter6"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "6: Conducting Materials"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.1, Page number 170"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nm = 9.1*10**-31;          #mass of electron\nvf = 1*10**6;             #Fermi velocity(m/s)\ne = 1.6*10**-19;          #conversion factor from J to eV\n\n#Calculation\nEF = m*(vf**2)/(2*e);         #Fermi energy(eV)\nEF=math.ceil(EF*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"Fermi energy is\",EF,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Fermi energy is 2.85 eV\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.2, Page number 170"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nEF0 = 7.04;               #Fermi energy at 0K(eV)\nT = 300;                  #temperature(K)\nk = 1.38*10**-23;         #boltzmann constant\ne = 1.6*10**-19;          #conversion factor from J to eV\n\n#Calculation\nEF = EF0*(1-(((math.pi**2)/12)*(k*T/(EF0*e))**2));            #Fermi energy(eV)\nEF=math.ceil(EF*10**5)/10**5;   #rounding off to 5 decimals\n\n#Result\nprint \"Fermi energy is\",EF,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Fermi energy is 7.03993 eV\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.3, Page number 171"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nd = 2.7*10**3;          #density of Al(kg/m**3)\nMat = 27;               #atomic weight of Al\ntow = 10**-14;          #relaxation time(sec)\nNa = 6.022*10**23;       #avagadro constant\na = 3*10**3;             #number of free electrons per atom\ne = 1.6*10**-19;         #charge of electron\nme = 9.1*10**-31;        #mass of electron\n\n#Calculation\nn = d*Na*a/Mat;          #concentration of atoms(per m**3)\nsigma = n*e**2*tow/me;          #conductivity(ohm m)\nsigma = sigma*10**-7;\nsigma=math.ceil(sigma*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"conductivity of Al is\",sigma,\"*10**7 ohm m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "conductivity of Al is 5.0824 *10**7 ohm m\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.4, Page number 171"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nsigma = 5.87*10**7;         #electrical conductivity(per ohm m)\nK = 390;                    #thermal conductivity(W/mK)\nT = 20;                    #temperature(C)\n\n#Calculation\nT = T+273;                #temperature(K)\nL = K/(sigma*T);          #Lorentz number(W ohm/K**2)\n\n#Result\nprint \"Lorentz number is\",L,\"W ohm/K**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Lorentz number is 2.26756051189e-08 W ohm/K**2\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.5, Page number 172"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nd = 8900;          #density of Cu(kg/m**3)\nMat = 63.5;               #atomic weight of Cu\ntow = 10**-14;          #relaxation time(sec)\nNa = 6.022*10**23;       #avagadro constant\na = 1*10**3;             #number of free electrons per atom\ne = 1.6*10**-19;         #charge of electron\nme = 9.1*10**-31;        #mass of electron\n\n#Calculation\nn = d*Na*a/Mat;          #concentration of atoms(per m**3)\nsigma = n*e**2*tow/me;          #electrical conductivity(ohm m)\nsigma = sigma*10**-7;\nsigma=math.ceil(sigma*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"electrical conductivity is\",sigma,\"*10**7 ohm m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electrical conductivity is 2.3745 *10**7 ohm m\n"
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.6, Page number 172"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nrho = 1.54*10**-8;         #resistivity(ohm m)\nEF = 5.5;                  #fermi energy(eV)\nme = 9.1*10**-31;          #mass of electron\nepsilon = 100;\ne = 1.6*10**-19;           #charge of electron\nn = 5.8*10**28;            #concentration of electrons(per m**3)\n\n#Calculation\ntow = me/(rho*n*e**2);        #relaxation time(sec)\nmew = e*tow/me;               #mobility of electrons(m**2/Vs)\nmew = mew*10**3;\nvd = e*tow*epsilon/me;        #drift velocity(m/s)\nvd=math.ceil(vd*10)/10;   #rounding off to 1 decimal\nEF = EF*e;                    #fermi energy((J)\nvF = math.sqrt(2*EF/me);           #fermi velocity(m/s)\nvf = vF*10**-6;\nvf=math.ceil(vf*10**3)/10**3;   #rounding off to 3 decimals\nlamda_m = vF*tow;                  #mean free path(m)\n\n#Result\nprint \"relaxation time of electrons is\",tow,\"sec\"\nprint \"mobility of electrons is\",mew,\"*10**-3 m**2/Vs\"\nprint \"drift velocity of electrons is\",vd,\"m/s\"\nprint \"drift velocity given in the book is wrong\"\nprint \"fermi velocity of electrons is\",vf,\"*10**6 m/s\"\nprint \"mean free path is\",lamda_m,\"m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "relaxation time of electrons is 3.97972178683e-14 sec\nmobility of electrons is 6.9973130318 *10**-3 m**2/Vs\ndrift velocity of electrons is 0.7 m/s\ndrift velocity given in the book is wrong\nfermi velocity of electrons is 1.391 *10**6 m/s\nmean free path is 5.53462691011e-08 m\n"
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.7, Page number 174"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nrho = 1.72*10**-8;          #electrical resistivity(ohm m)\nL = 2.26*10**-8;            #Lorentz number(ohm W/K**2)\nT = 27;                     #temperature(C)\n\n#Calculation\nT = T+273;                #temperature(K)\nK = L*T/rho;          #thermal conductivity(W/mK)\n\n#Result\nprint \"thermal conductivity is\",int(K),\"W/mK\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "thermal conductivity is 394 W/mK\n"
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.8, Page number 174"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nsigma = 5.87*10**7;         #electrical conductivity(per ohm m)\nK = 390;                    #thermal conductivity(W/mK)\nT = 20;                    #temperature(C)\n\n#Calculation\nT = T+273;                #temperature(K)\nL = K/(sigma*T);          #Lorentz number(W ohm/K**2)\n\n#Result\nprint \"Lorentz number is\",L,\"W ohm/K**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Lorentz number is 2.26756051189e-08 W ohm/K**2\n"
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.9, Page number 174"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nE_EF = 0.01;               #energy(eV)\ne = 1.6*10**-19;           #conversion factor from eV to J\nT = 200;                    #temperature(K)\nk = 1.38*10**-23;           #boltzmann constant(J/K)\n\n#Calculation\nE_EF = E_EF*e;            #energy(J)\nA = E_EF/(k*T);\nFofE = 1/(1+(math.exp(A)));           #value of F(E)\nFofE=math.ceil(FofE*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"value of F(E) is\",FofE",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "value of F(E) is 0.36\n"
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.10, Page number 175"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nlamda = 4*10**-8;     #mean free path(m)\nn = 8.4*10**28;          #density(per m**3)\nvthbar = 1.6*10**6;        #average thermal velocity(m/s)\ne = 1.6*10**-19;         #charge of electron(c)\nm = 9.11*10**-31;        #mass of electron\n\n#Calculation\nsigma = n*e**2*lamda/(m*vthbar);        #electrical conductivity(ohm-1 m-1)\nsigma = sigma*10**-7;\nsigma=math.ceil(sigma*100)/100;   #rounding off to 2 decimals\n\n#Result\nprint \"electrical conductivity is\",sigma,\"*10**7 ohm-1 m-1\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electrical conductivity is 5.91 *10**7 ohm-1 m-1\n"
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.11, Page number 176"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ntow = 10**-14;         #relaxation time(sec)\nT = 300;               #temperature(K)\nn = 6*10**28;          #electron concentration(per m**3)\ne = 1.6*10**-19;         #charge of electron(c)\nme = 9.1*10**-31;        #mass of electron\nk = 1.38*10**-23;           #boltzmann constant(J/K)\n\n#Calculation\nsigma = n*e**2*tow/me;        #electrical conductivity(ohm-1 m-1)\nsigmaa = sigma*10**-7;\nsigmaa=math.ceil(sigmaa*100)/100;   #rounding off to 2 decimals\nK = 3*n*(k**2)*tow*T/(2*me);           #thermal conductivity(W/mK)\nK=math.ceil(K*10)/10;   #rounding off to 1 decimal\nL = K/(sigma*T);         #Lorentz number(W ohm/K**2)\n\n#Result\nprint \"electrical conductivity is\",sigmaa,\"*10**7 ohm-1 m-1\"\nprint \"thermal conductivity is\",K,\"W/mK\"\nprint \"Lorentz number is\",L,\"W ohm/K**2\"\nprint \"answer for thermal conductivity and Lorentz number given in the book are wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electrical conductivity is 1.69 *10**7 ohm-1 m-1\nthermal conductivity is 56.6 W/mK\nLorentz number is 1.11775173611e-08 W ohm/K**2\nanswer for thermal conductivity and Lorentz number given in the book are wrong\n"
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.12, Page number 177"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nn = 5.8*10**28;          #electron concentration(per m**3)\ne = 1.6*10**-19;         #charge of electron(c)\nm = 9.1*10**-31;        #mass of electron\nrho = 1.54*10**-8;       #resistivity of metal(ohm m)\n\n#Calculation\ntow = m/(n*rho*e**2);         #relaxation time(sec)\n\n#Result\nprint \"relaxation time is\",tow,\"sec\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "relaxation time is 3.97972178683e-14 sec\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.13, Page number 177"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nrho = 1.54*10**-8;         #resistivity(ohm m)\nE = 1;                  #electric field(V/cm)\nme = 9.1*10**-31;          #mass of electron\ne = 1.6*10**-19;           #charge of electron\nn = 5.8*10**28;            #concentration of electrons(per m**3)\n\n#Calculation\nE = E*10**2;            #electric field(V/m)\ntow = me/(rho*n*e**2);        #relaxation time(sec)\nvd = e*E*tow/me;        #drift velocity(m/s)\nvd=math.ceil(vd*10)/10;   #rounding off to 1 decimal\nmew = vd/E;               #mobility of electrons(m**2/Vs)\nmew = mew*10**2;\n\n#Result\nprint \"relaxation time of electrons is\",tow,\"sec\"\nprint \"drift velocity of electrons is\",vd,\"m/s\"\nprint \"mobility of electrons is\",mew,\"*10**-2 m**2/Vs\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "relaxation time of electrons is 3.97972178683e-14 sec\ndrift velocity of electrons is 0.7 m/s\nmobility of electrons is 0.7 *10**-2 m**2/Vs\n"
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.14, Page number 178"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nT = 300;                   #temperature(K)\nl = 2;                     #length of wire(m)\nR = 0.02;                  #resistance(ohm)\nI = 15;                    #current(amp)\nmew = 4.3*10**-3;          #mobility(m**2/Vs)\n\n#Calculation\nV = I*R;                   #voltage drop(V)\nE = V/l;                   #electric field(V/m)\nvd = mew*E;                #drift velocity(m/s)\nvd = vd*10**3;\nvd=math.ceil(vd*100)/100;   #rounding off to 2 decimals\n\n#Result\nprint \"drift velocity of electrons is\",vd,\"*10**-3 m/s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "drift velocity of electrons is 0.65 *10**-3 m/s\n"
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.15, Page number 179"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nvf = 0.86*10**6;          #fermi velocity(m/s)\nm = 9.1*10**-31;          #mass of electron(kg)\ne = 1.6*10**-19;          #charge of electron(C)\nk = 1.38*10**-23;         #boltzmann constant\n\n#Calculation\nEF = m*vf**2/(2*e);       #fermi energy(eV)\nEF=math.ceil(EF*100)/100;   #rounding off to 2 decimals\nTF = EF*e/k;                  #fermi temperature(K)\n\n#Result\nprint \"Fermi energy is\",EF,\"eV\"\nprint \"Fermi temperature is\",int(TF),\"K\"\nprint \"answer for fermi temperature given in the book is wrong due to rounding off the value of EF\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Fermi energy is 2.11 eV\nFermi temperature is 24463 K\nanswer for fermi temperature given in the book is wrong due to rounding off the value of EF\n"
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 6.16, Page number 179"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nTF = 2460;            #fermi temperature(K)\nm = 9.11*10**-31;          #mass of electron(kg)\nk = 1.38*10**-23;         #boltzmann constant\n\n#Calculation\nvF = math.sqrt(2*k*TF/m);          #fermi velocity(m/s)\nvF = vF*10**-5;\nvF=math.ceil(vF*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"Fermi velocity is\",vF,\"*10**5 m/s\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Fermi velocity is 2.731 *10**5 m/s\n"
+      }
+     ],
+     "prompt_number": 16
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter7.ipynb b/Engineering_Physics/Chapter7.ipynb
new file mode 100755
index 00000000..d6a7ab3d
--- /dev/null
+++ b/Engineering_Physics/Chapter7.ipynb
@@ -0,0 +1,468 @@
+{
+ "metadata": {
+  "name": "Chapter7",
+  "signature": "sha256:043709ddd748250fcd3232cc251c6d71d665f281189e172a4c8d9b59233bdcee"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "7: Semiconducting Materials"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.1, Page number 208"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nme = 9.11*10**-31;          #mass of electron(kg)\nepsilon_r = 13.2;  \nepsilon0 = 8.85*10**-12;\nh = 6.63*10**-34;\ne = 1.6*10**-19;          #charge of electron(C)\n\n#Calculation\nm_nc = 0.067*me;\nE = m_nc*e**4/(8*(epsilon0*epsilon_r*h)**2);       #energy(J)\nE = E/e;                #energy(eV)\nE = math.ceil(E*10**5)/10**5;   #rounding off to 5 decimals\nE_meV = E*10**3;        #energy(meV)\n\n#Result\nprint \"donor binding energy is\",E,\"eV or\",E_meV,\"meV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "donor binding energy is 0.00521 eV or 5.21 meV\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.2, Page number 208"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nimport numpy as np\n\n#Variable declaration\nNd = 10**16;         #donor concentration(atoms/cm**3)\nni = 1.5*10**10;        #concentration(per cm**3)\nT = 300;                #temperature(K)\nkT = 0.0259;\n\n#Calculation\nn0 = Nd;           #for Nd>>ni, assume n0=Nd\np0 = ni**2/n0;        #equilibrium hole concentration(per cm**3)\np0 = p0*10**-4;\nEF_Ei = kT*np.log(n0/ni);\nEF_Ei = math.ceil(EF_Ei*10**4)/10**4;   #rounding off to 4 decimals\n\n\n#Result\nprint \"equilibrium hole concentration is\",p0,\"*10**4 per cm**3\"\nprint \"value of EF-Ei is\",EF_Ei,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "equilibrium hole concentration is 2.25 *10**4 per cm**3\nvalue of EF-Ei is 0.3474 eV\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.3, Page number 209"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;          #charge of electron(C)\nNd = 10**14;              #donor density(atoms/cm**3)\nmew_n = 3900;\n\n#Calculation\nn = Nd;\nsigma = n*e*mew_n;        #conductivity(ohm-1 cm-1)\nrho = 1/sigma;            #resistivity(ohm cm)\nrho = math.ceil(rho*100)/100;   #rounding off to 2 decimals\n\n\n#Result\nprint \"resistivity of sample is\",rho,\"ohm cm\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "resistivity of sample is 16.03 ohm cm\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.4, Page number 209"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;          #charge of electron(C)\nn0 = 5*10**16;              #donor density(atoms/cm**3)\nmew_0 = 800;\nIx = 2;             #current(mA)\nBz = 5*10**-5;\nd = 200;            #thickness(micrometre)\n\n#Calculation\nIx = Ix*10**-3;          #current(A)\nd = d*10**-4;            #thickness(m)\nsigma = e*n0*mew_0;        #conductivity(ohm-1 cm-1)\nrho = 1/sigma;            #resistivity(ohm cm)\nrho = math.ceil(rho*10**4)/10**4;   #rounding off to 4 decimals\nRH = -1/(e*n0);          #Hall coefficient(cm**3/C)\nVH = Ix*Bz*RH/d;         #Hall voltage(V)\nVH = VH*10**5;\n\n\n#Result\nprint \"resistivity of sample is\",rho,\"ohm cm\"\nprint \"Hall coefficient is\",RH,\"cm**3/C\"\nprint \"Hall voltage is\",VH,\"*10**-5 V\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "resistivity of sample is 0.1563 ohm cm\nHall coefficient is -125.0 cm**3/C\nHall voltage is -62.5 *10**-5 V\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.5, Page number 210"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nT = 300;          #temperature(K)\nmew_n = 0.4;      #electron mobility(m**2/Vs)\nmew_p = 0.2;      #hole mobility(m**2/Vs)\nEg = 0.7;         #band gap(eV)\nme = 9.11*10**-31;       #mass of electron(kg)\nk = 1.38*10**-23;        #boltzmann constant\nT = 300;                 #temperature(K)\nh = 6.625*10**-34;\nkT = 0.0259;\ne = 1.6*10**-19;          #charge of electron(C)\n\n#Calculation\nmn_star = 0.55*me;           #electron effective mass(kg)\nmp_star = 0.37*me;           #hole effective mass(kg)\na = (2*math.pi*k*T/(h**2))**(3/2);\nb = (mn_star*mp_star)**(3/4);\nc = math.exp(-Eg/(2*kT));\nni = 2*a*b*c;     #intrinsic concentration(per m**3)\nsigma = ni*e*(mew_n+mew_p);               #intrinsic conductivity(per ohm m)\nsigma = math.ceil(sigma*10**4)/10**4;   #rounding off to 4 decimals\nrho = 1/sigma;                            #intrinsic resistivity(ohm m)\nrho = math.ceil(rho*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"intrinsic concentration is\",ni,\"per m**3\"\nprint \"intrinsic conductivity is\",sigma,\"per ohm m\"\nprint \"intrinsic resistivity is\",rho,\"ohm m\"\nprint \"answers given in the book are wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "intrinsic concentration is 1.02825111151e+19 per m**3\nintrinsic conductivity is 0.9872 per ohm m\nintrinsic resistivity is 1.013 ohm m\nanswers given in the book are wrong\n"
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.6, Page number 211"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nimport numpy as np\nfrom __future__ import division\n\n#Variable declaration\nNd = 10**16;           #donor concentration(per cm**3)\nni = 1.45*10**10;         #concentration(per cm**3)\nkT = 0.0259;\n\n#Calculation\n#ni = Nc*math.exp(-(Ec-Ei)/kT)\n#Nd = Nc*(math.exp(-(Ec-Efd)/kT)\n#dividing Nd/ni we get \nEFd_Ei = kT*np.log(Nd/ni);\nEFd_Ei = math.ceil(EFd_Ei*10**4)/10**4;   #rounding off to 4 decimals\n\n#Result\nprint \"Fermi energy is\",EFd_Ei,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Fermi energy is 0.3482 eV\n"
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.7, Page number 211, theoretical"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.8, Page number 212"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nimport numpy as np\nfrom __future__ import division\n\n#Variable declaration\nT = 300;          #temperature(K)\nmew_n = 0.36;      #electron mobility(m**2/Vs)\nmew_p = 0.17;      #hole mobility(m**2/Vs)\nrho = 2.12;         #resistivity(ohm m)\nme = 9.11*10**-31;       #mass of electron(kg)\nkT = 0.0259;\nh = 6.625*10**-34;\nk = 1.38*10**-23;        #boltzmann constant\ne = 1.6*10**-19;          #charge of electron(C)\n\n#Calculation\nmn_star = 0.55*me;           #electron effective mass(kg)\nmp_star = 0.37*me;           #hole effective mass(kg)\nsigma = 1/rho;               #conductivity(per ohm m)\nsigma = math.ceil(sigma*10**3)/10**3;   #rounding off to 3 decimals\nni = sigma/(e*(mew_n+mew_p));          #concentration of electrons(per m**3)\na = (2*math.pi*kT/(h**2))**(3/2);\nNc = 2*a*(mn_star**(3/2)); \nNv = 2*a*(mp_star**(3/2)); \nb = (Nc*Nv)**(1/2);\nEg = 2*kT*np.log(b/ni);\n\n#Result\nprint \"forbidden energy gap is\",Eg,\"eV\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "forbidden energy gap is 4.09465494989 eV\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.9, Page number 213"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nni = 2.4*10**19;       #concentration(per m**3)\nmew_n = 0.39;      #electron mobility(m**2/Vs)\nmew_p = 0.19;      #hole mobility(m**2/Vs)\ne = 1.6*10**-19;          #charge of electron(C)\n\n#Calculation\nsigma = ni*e*(mew_n+mew_p);         #conductivity(per ohm m)\nsigma = math.ceil(sigma*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"conductivity of sample is\",sigma,\"ohm-1 m-1\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "conductivity of sample is 2.228 ohm-1 m-1\n"
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.10, Page number 214"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nEc = 0.3;          #initial position(eV)\nT1 = 300;           #initial temperature(K)\nT2 = 330;           #increased temperature\n\n#Calculation\n#Ec/T1 = Ec_EF330/T2\nEc_EF330 = Ec*T2/T1;        #new position of Fermi level(eV)\n\n#Result\nprint \"new position of Fermi level is\",Ec_EF330,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "new position of Fermi level is 0.33 eV\n"
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.11, Page number 214"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nk = 1.38*10**-23;         #boltzmann constant\nT = 300;           #temperature(K)\nme = 9.1*10**-31;        #mass of electron(kg)\nh = 6.63*10**-34;        #planck's constant\nEc_Ev = 1.1;             #energy gap(eV)\ne = 1.6*10**-19;         #charge of electron(C)\n\n#Calculation\nme_star = 0.31*me;\nA = (2*math.pi*k*T*me_star/(h**2))**(3/2);\nB = math.exp(-(Ec_Ev*e)/(2*k*T));\nni = A*B;                  #concentration in conduction band(per m**3)\n\n#Result\nprint \"intrinsic electron concentration is\",ni,\"per m**3\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "intrinsic electron concentration is 1.26605935487e+15 per m**3\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.12, Page number 214"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nRH = 0.55*10**-10;          #Hall coefficient(m**3/As)\nsigma = 5.9*10**7;          #conductivity(ohm-1 m-1)\n\n#Calculation\nmew = RH*sigma;              #drift mobility(m**2/Vs)\nmew = mew*10**3;\nmew = math.ceil(mew*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"drift mobility of electrons is\",mew,\"*10**-3 m**2/Vs\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "drift mobility of electrons is 3.25 *10**-3 m**2/Vs\n"
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.13, Page number 215"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nA = 6.022*10**23;           #avagadro constant\nd = 8.96*10**-9;            #density(kg/m**3)\nn = 9.932*10**14;           #no. of free electrons per atom\nsigma = 5.9*10**7;          #conductivity(ohm-1 m-1)\ne = 1.6*10**-19;            #electron charge(C)\nmew = 3.2*10**-3;           #drift mobility(m**2/Vs)\nw = 63.5;                   #atomic weight of Cu(kg)\n\n#Calculation\nni = sigma/(mew*e);         #conductivity(per m**3)\nN = A*d*n/w;                #concentration of free electrons in pure Cu\nAN = ni/N;                  #average number of electrons contributed per Cu atom\n\n#Result\nprint \"concentration of free electrons in pure Cu is\",N,\"per m**3\"\nprint \"average number of electrons contributed per Cu atom is\",int(AN)",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "concentration of free electrons in pure Cu is 8.43940339906e+28 per m**3\naverage number of electrons contributed per Cu atom is 1\n"
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.14, Page number 215"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nRH = 3.66*10**-11;          #hall coefficient(m**3/As)\ne = 1.6*10**-19;            #electron charge(C)\nsigma = 112*10**7;          #conductivity(ohm-1 m-1)\n\n#Calculation\nn = 1/(e*RH);               #charge carrier density(per m**3)\nmew_n = sigma/(n*e);        #electron mobility(m**2/As)\nmew_n = math.ceil(mew_n*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"charge carrier density is\",n,\"per m**3\"\nprint \"electron mobility is\",mew_n,\"m**2/As\"\nprint \"answers given in the book are wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "charge carrier density is 1.70765027322e+29 per m**3\nelectron mobility is 0.041 m**2/As\nanswers given in the book are wrong\n"
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.15, Page number 216"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nB = 1.5;                    #magnetic field(T)\nI = 50;                     #current(Amp)\nn = 8.4*10**28;             #free electron concentration(per m**3)\nd = 0.2;                    #thickness of slab(cm)\n\n#Calculation\nd = d*10**-2;               #thickness of slab(m)\nVH = B*I/(n*e*d);           #hall voltage(V)\n\n#Result\nprint \"magnitude of Hall voltage is\",VH,\"V\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "magnitude of Hall voltage is 2.79017857143e-06 V\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.16, Page number 216"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nn = 2.5*10**19;             #free electron concentration(per m**3)\nmew_n = 0.39;               #electron mobility(m**2/Vs)\nmew_p = 0.19;               #hole mobility(m**2/Vs)\nL = 1;                      #length(cm)\nw = 1;                      #width(mm)\nt = 1;                      #thickness(mm)\n\n#Calculation\nL = L*10**-2;               #length(m)\nw = w*10**-3;               #width(m)\nt = t*10**-3;               #thickness(m)\nA = w*t;                    #area(m**2)\nsigma = n*e*(mew_n+mew_p);         #conductivity(ohm-1 m-1)\nR = L/(sigma*A);                   #resistance(ohm)\n\n#Result\nprint \"resistance of intrinsic Ge rod is\",int(R),\"ohm\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "resistance of intrinsic Ge rod is 4310 ohm\n"
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.17, Page number 216"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nimport numpy as np\nfrom __future__ import division\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nEg = 1.12;                  #band gap(eV)\nme = 1;\nmn_star = 0.12*me;               #electron mobility(m**2/Vs)\nmp_star = 0.28*me;               #hole mobility(m**2/Vs)\nk = 1.38*10**-23;                #boltzmann constant\nT = 300;                         #temperature\n\n#Calculation\na = mp_star/mn_star;\nEF = (Eg/2)+((3*k*T/(4*e))*np.log(a));\nEF = math.ceil(EF*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"position of Fermi level is\",EF,\"eV\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "position of Fermi level is 0.577 eV\n"
+      }
+     ],
+     "prompt_number": 17
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.18, Page number 217"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nni = 1.5*10**16;            #intrinsic carrier density(per m**3)\nmew_n = 0.13;               #electron mobility(m**2/Vs)\nmew_p = 0.05;               #hole mobility(m**2/Vs)\n\n#Calculation\nsigma = ni*e*(mew_n+mew_p);        #electrical conductivity\nsigma = sigma*10**4;\n\n#Result\nprint \"electrical conductivity is\",sigma,\"*10**-4 ohm-1 m-1\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "electrical conductivity is 4.32 *10**-4 ohm-1 m-1\n"
+      }
+     ],
+     "prompt_number": 18
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.19, Page number 217"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nni = 2.15*10**-13;            #intrinsic carrier density(per cm**3)\nmew_n = 3900;               #electron mobility(cm**2/Vs)\nmew_p = 1900;               #hole mobility(cm**2/Vs)\n\n#Calculation\nsigmai = ni*e*(mew_n+mew_p);        #electrical conductivity(ohm-1 cm-1)\nrhoi = 1/sigmai;                    #intrinsic resistivity(ohm cm)\n\n#Result\nprint \"intrinsic resistivity is\",rhoi,\"ohm cm\"\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "intrinsic resistivity is 5.01202886929e+27 ohm cm\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 19
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.20, Page number 217"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nni = 2.1*10**19;            #intrinsic carrier density(per m**3)\nmew_n = 0.4;               #electron mobility(m**2/Vs)\nmew_p = 0.2;               #hole mobility(m**2/Vs)\n\n#Calculation\nsigma = ni*e*(mew_n+mew_p);        #electrical conductivity\n\n#Result\nprint \"intrinsic resistivity is\",sigma,\"ohm-1 m-1\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "intrinsic resistivity is 2.016 ohm-1 m-1\n"
+      }
+     ],
+     "prompt_number": 20
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.21, Page number 218"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nV = 1.35;                   #voltage supply(V)\nI = 5;               #current(mA)\nb = 5;               #breadth(mm)\nd = 1;               #thickness(mm)\nL = 1;               #length(cm)\nH = 0.45;            #magnetic field(Wb/m**2)\nVy =20;              #Hall voltage(mV)\n\n#Calculation\nVy = Vy*10**-3;       #Hall voltage(V)\nL = L*10**-2;         #length(m)\nd = d*10**-3;         #thickness(m)\nb = b*10**-3;         #breadth(m)\nI = I*10**-3;         #current(A)\nR = V/I;              #resistance(ohm)\nA = b*d;              #area(m**2)\nrho = R*A/L;          #resistivity(ohm m)\nEy = Vy/d;            #Hall field(V/m)\nJx = I/A;           \na = Ey/(H*Jx);         #current density(m**3/C).Here a is 1/ne \nRH = a;               #Hall coefficient(m**3/C)\nRH = math.ceil(RH*10**4)/10**4;   #rounding off to 4 decimals\nmew_n = RH/rho;       #electron mobility(m**2/Vs)\nmew_n = math.ceil(mew_n*10**2)/10**2;   #rounding off to 2 decimals\n\n#Result\nprint \"Hall coefficient is\",RH,\"m**3/C\"\nprint \"electron mobility is\",mew_n,\"m**2/Vs\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Hall coefficient is 0.0445 m**3/C\nelectron mobility is 0.33 m**2/Vs\n"
+      }
+     ],
+     "prompt_number": 21
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 7.22, Page number 219"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\ne = 1.6*10**-19;            #electron charge(C)\nIx = 200;               #current(A)\nBz = 1.5;               #magnetic field(Wb/m**2)\np = 8.4*10**28;         #electron concentration(per m**3)\nd = 1;               #thickness(mm)\n\n#Calculation\nd = d*10**-3;         #thickness(m)\nVH = Ix*Bz/(e*p*d);         #Hall potential(V)\nVH = VH*10**6;              #Hall potential(micro V)\n\n#Result\nprint \"Hall potential is\",int(VH),\"micro V\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "Hall potential is 22 micro V\n"
+      }
+     ],
+     "prompt_number": 22
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter8.ipynb b/Engineering_Physics/Chapter8.ipynb
new file mode 100755
index 00000000..54d83b1d
--- /dev/null
+++ b/Engineering_Physics/Chapter8.ipynb
@@ -0,0 +1,125 @@
+{
+ "metadata": {
+  "name": "Chapter8"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "8: Magnetic Materials"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 8.1, Page number 238"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nI = 12;          #current(Ampere)\nA = 7.5*10**-4       #area of loop(m**2)\n\n#Calculation\nM = I*A;         #magnetic moment(Am**2)\nM = M*10**3;\n\n#Result\nprint \"magnetic moment is\",M,\"*10**-3 Am**2\"\nprint \"magnetic moment is in opposite direction from the observer\"\nprint \"M is perpendicular to the plane\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "magnetic moment is 9.0 *10**-3 Am**2\nmagnetic moment is in opposite direction from the observer\nM is perpendicular to the plane\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 8.2, Page number 238"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nr = 0.5;         #radius of orbit(Angstrom)\ne = 1.6*10**-19;       #charge of electron(C)\nnew = 10**16;          #frequency(rps)\n\n#Calculation\nr = r*10**-10;         #radius of orbit(m)\nI = e*new;             #current(Ampere)\nA = math.pi*r**2;      #area enclosed(m**2)\nM = I*A;               #magnetic moment(Am**2)\n\n#Result\nprint \"magnetic moment is\",M,\"Am**2\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "magnetic moment is 1.25663706144e-23 Am**2\n"
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 8.3, Page number 239"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nmew_r = 5000;       #relative permeability\n\n#Calculation\nchi_m = mew_r-1;       #magnetic susceptibility\n\n#Result\nprint \"magnetic susceptibility is\",chi_m",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "magnetic susceptibility is 4999\n"
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 8.4, Page number 239"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nH = 1800;       #magnetic field(A/m)\nphi = 3*10**-5;         #magnetic flux(Wb)\nA = 0.2;           #cross sectional area(cm**2)\n\n#Calculation\nA = A*10**-4;      #cross sectional area(m**2)\nB = phi/A;         #magnetic flux density(Wb/m**2)\nmew = B/H;         #permeability(H/m)\nmew = mew*10**4;\nmew=math.ceil(mew*100)/100;   #rounding off to 2 decimals\n\n#Result\nprint \"permeability is\",mew,\"*10**-4 H/m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "permeability is 8.34 *10**-4 H/m\n"
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 8.5, Page number 239"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nB = 0.65;      #magnetic induction(Wb/m**2)\nrho = 8906;       #density(kg/m**3)\nM = 58.7;         #atomic weight\nmew0 = 4*math.pi*10**-7;\nmb = 9.27*10**-24;\nNa = 6.023*10**26;      #avagadro constant\n\n#Calculation\nN = rho*Na/M;         #number of atoms per unit volume(atoms/m**3)\nmew_r = B/(N*mew0);         #relative permeability(A/m**2)\nM = mew_r/mb;               #magnetic moment in mew_B \nM=math.ceil(M*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"magnetic moment is\",M,\"mew_B\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "magnetic moment is 0.611 mew_B\n"
+      }
+     ],
+     "prompt_number": 5
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/Chapter9.ipynb b/Engineering_Physics/Chapter9.ipynb
new file mode 100755
index 00000000..ff53dd34
--- /dev/null
+++ b/Engineering_Physics/Chapter9.ipynb
@@ -0,0 +1,62 @@
+{
+ "metadata": {
+  "name": "Chapter9"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": "9: Superconducting Materials"
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 9.1, Page number 255"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nH0 = 6.5*10**4;         #magnetic field intensity(A/m)\nT = 4.2;                #temperature(K)\nTc = 7.18;              #critical temperature(K)\n\n#Calculation\nHc = H0*(1-((T**2)/(Tc**2)));        #critical magnetic field intensity(A/m)\nHc = Hc*10**-4;\nHc=math.ceil(Hc*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"critical magnetic field intensity is\",Hc,\"*10**4 A/m\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "critical magnetic field intensity is 4.276 *10**4 A/m\n"
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": "Example number 9.2, Page number 255"
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": "#importing modules\nimport math\n\n#Variable declaration\nTc1 = 4.185;                #critical temperature for M1(K)\nTc2 = 4.133;                #critical temperature for M2(K)\nM1 = 199.5;                 #isotopic mass\nalpha = 0.5;\n\n#Calculation\nA = math.pow(M1,alpha)*Tc1/Tc2;\nM2 = math.pow(A,1/alpha);       #isotopic mass\nM2=math.ceil(M2*10**3)/10**3;   #rounding off to 3 decimals\n\n#Result\nprint \"isotopic mass is\",M2\nprint \"answer given in the book is wrong\"",
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": "isotopic mass is 204.552\nanswer given in the book is wrong\n"
+      }
+     ],
+     "prompt_number": 2
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Engineering_Physics/README.txt b/Engineering_Physics/README.txt
new file mode 100755
index 00000000..bd7c4bfa
--- /dev/null
+++ b/Engineering_Physics/README.txt
@@ -0,0 +1,10 @@
+Contributed By: KRISHNA CHAITANYA
+Course: btech
+College/Institute/Organization: JNTUH
+Department/Designation: Computer Science
+Book Title: Engineering Physics
+Author: D. K. Bhattacharya & A. Bhaskaran
+Publisher: Oxford University Press, New Delhi
+Year of publication: 2013
+Isbn: 9780198065425
+Edition: 1
\ No newline at end of file
diff --git a/Engineering_Physics/screenshots/Untitled1.png b/Engineering_Physics/screenshots/Untitled1.png
new file mode 100755
index 00000000..2584f5af
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled1.png
diff --git a/Engineering_Physics/screenshots/Untitled1_1.png b/Engineering_Physics/screenshots/Untitled1_1.png
new file mode 100755
index 00000000..6c937ec4
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled1_1.png
diff --git a/Engineering_Physics/screenshots/Untitled2.png b/Engineering_Physics/screenshots/Untitled2.png
new file mode 100755
index 00000000..7461d551
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled2.png
diff --git a/Engineering_Physics/screenshots/Untitled2_1.png b/Engineering_Physics/screenshots/Untitled2_1.png
new file mode 100755
index 00000000..a47a6ec9
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled2_1.png
diff --git a/Engineering_Physics/screenshots/Untitled3.png b/Engineering_Physics/screenshots/Untitled3.png
new file mode 100755
index 00000000..492ad660
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled3.png
diff --git a/Engineering_Physics/screenshots/Untitled3_1.png b/Engineering_Physics/screenshots/Untitled3_1.png
new file mode 100755
index 00000000..cdbc1a6f
--- /dev/null
+++ b/Engineering_Physics/screenshots/Untitled3_1.png