Added(A)/Deleted(D) following books

 A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_1Zann0J.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3R4x1st.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3njJQNW.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3nqQG4m.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_4GlnKNw.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_55ZHPE1.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_7vAWWtf.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_8k98KXK.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_9epeI5v.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_CEeTHUJ.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_E1eRmp6.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_GQ8CWIs.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_HEd5C4N.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_IlcYN96.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_Jn2jAxR.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_L5T0xXa.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_NHRNirZ.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PE2KT6W.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PKCP8ZY.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PMopwvn.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_TxLgaXP.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_UQP2Hbl.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_X8mfBi8.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_YHbAZL8.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_arYa4fL.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_bIyaeBj.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_d87uZsb.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dJzyQXE.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dV9ikYe.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_e7YLoLd.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_eHnfttn.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_fh4Y4P5.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_hbRKWYG.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_icFPVil.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_kEBkdeu.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_lSt1FDp.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_oqU54mr.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_rcid83s.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_s0Hwrru.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_ufxQ3hX.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yU7SECk.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yZCyjq6.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yrMGHYH.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zKQXNUB.ipynb
A  Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zYPve8I.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter10_jNQZCoy.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter11_xIicyr8.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter12_1G5pKOe.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter1_gdrng9U.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter2_RLHLaga.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter3_PZ90WhS.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter4_WU1E9Hg.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter5_DR2oZl3.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter6_qpsBdAt.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter7_e6YYQO5.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter8_ZfKCkQQ.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter9_eHYvPeL.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter13_O3kovtd.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter14_Tw2n7GH.ipynb
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/screenshots/Chapter1_P3ZB3KT.png
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/screenshots/Chapter1_qIYXBB9.png
A  Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/screenshots/Chapter5_KmacWXe.png

62 files changed, 21825 insertions, 0 deletions

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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 1: Atomic Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 55"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of emitted photon is 1.281 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=3;\n",
+    "n2=5;        #states\n",
+    "RH=1.0977*10**7;\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=RH*((1/n1**2)-(1/n2**2));\n",
+    "lamda=10**6/newbar;         #wavelength of emitted photon(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of emitted photon is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of principal quantum number of two orbits is 14 / 11\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "E1=1.21;\n",
+    "E2=1.96;        #energy of two orbits(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n1=math.sqrt(E2);\n",
+    "n2=math.sqrt(E1);       #ratio of principal quantum number of two orbits\n",
+    "n1=n1*10;\n",
+    "n2=n2*10;               #multiply and divide the ratio by 10\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of principal quantum number of two orbits is\",int(n1),\"/\",int(n2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment of proton is 5.041 *10**-27 Am**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "mp=1.672*10**-27;         #mass of electron(kg)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewp=e*h/(4*math.pi*mp);  #magnetic moment of proton(Am**2) \n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment of proton is\",round(mewp*10**27,3),\"*10**-27 Am**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "specific charge of electron is 1.7604 *10**11 coulomb/kg\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "mewB=9.274*10**-24;       #bohr magneton(amp m**2)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "ebym=mewB*4*math.pi/h;    #specific charge of electron(coulomb/kg)      \n",
+    "\n",
+    "#Result\n",
+    "print \"specific charge of electron is\",round(ebym/10**11,4),\"*10**11 coulomb/kg\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength separation is 0.3358 angstrom\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "B=1;                #flux density(Wb/m**2)\n",
+    "lamda=6000*10**-10; #wavelength(m)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "c=3*10**8;          #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "d_lamda=B*e*(lamda**2)/(4*math.pi*m*c);     #wavelength separation(m)\n",
+    "d_lamda=2*d_lamda*10**10;                   #wavelength separation(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength separation is\",round(d_lamda,4),\"angstrom\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of electron in 1st and 2nd orbit is -13.6 eV and -3.4 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        #states\n",
+    "\n",
+    "#Calculations\n",
+    "E1=-13.6/n1**2;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-13.6/n2**2;     #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of electron in 1st and 2nd orbit is\",E1,\"eV and\",E2,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "linear momentum is 2.107 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "lamda=0.5*10**-10;        #radius of 1st orbit(m)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "L=h/(2*math.pi*lamda);    #linear momentum(kg ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"linear momentum is\",round(L*10**24,3),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "state to which it is excited is 4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "E1=-13.6;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-12.75;    #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n=math.sqrt(-E1/(E2-E1));    #state to which it is excited\n",
+    "\n",
+    "#Result\n",
+    "print \"state to which it is excited is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "bohr magneton is 9.262 *10**-24 coulomb Js kg-1\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "h=6.62*10**-34;         #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewB=e*h/(4*math.pi*m);  #bohr magneton(coulomb Js kg-1) \n",
+    "\n",
+    "#Result\n",
+    "print \"bohr magneton is\",round(mewB*10**24,3),\"*10**-24 coulomb Js kg-1\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "component separation is 2.7983 *10**8 Hz\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "B=0.02;                 #magnetic field(T)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=e*B/(4*math.pi*m);    #component separation(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"component separation is\",round(delta_new/10**8,4),\"*10**8 Hz\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 61"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic flux density is 2.14 Tesla\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=10000*10**-10;    #wavelength(m)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "d_lamda=1*10**-10;      #wavelength separation(m)\n",
+    "\n",
+    "#Calculations\n",
+    "B=d_lamda*4*math.pi*m*c/(e*lamda**2);      #magnetic flux density(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic flux density is\",round(B,2),\"Tesla\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 19, Page number 66"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "separation is 0.33 angstrom\n",
+      "wavelength of three components is 4226 angstrom 4226.33 angstrom 4226.666 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=4226;             #wavelength(angstrom)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "B=4;                    #magnetic field(Wb/m**2)\n",
+    "\n",
+    "#Calculations\n",
+    "dnew=B*e/(4*math.pi*m);    \n",
+    "dlamda=lamda**2*dnew*10**-10/c;      #separation(angstrom)\n",
+    "dlamda1=lamda+dlamda;\n",
+    "dlamda2=dlamda1+dlamda;    #wavelength of three components(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"separation is\",round(dlamda,2),\"angstrom\"\n",
+    "print \"wavelength of three components is\",lamda,\"angstrom\",round(dlamda1,2),\"angstrom\",round(dlamda2,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 21, Page number 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of elements would be 110\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        \n",
+    "n3=3;\n",
+    "n4=4;\n",
+    "n5=5;\n",
+    "\n",
+    "#Calculations\n",
+    "e1=2*n1**2;     #maximum number of electrons in 1st orbit\n",
+    "e2=2*n2**2;     #maximum number of electrons in 2nd orbit\n",
+    "e3=2*n3**2;     #maximum number of electrons in 3rd orbit\n",
+    "e4=2*n4**2;     #maximum number of electrons in 4th orbit\n",
+    "e5=2*n5**2;     #maximum number of electrons in 5th orbit\n",
+    "e=e1+e2+e3+e4+e5;      #number of elements\n",
+    "\n",
+    "#Result\n",
+    "print \"number of elements would be\",e"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3R4x1st.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3R4x1st.ipynb
new file mode 100644
index 00000000..3725056f
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3R4x1st.ipynb
@@ -0,0 +1,243 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 13: Bonding In Crystals"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential energy is -5.76 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "r0=2.5*10**-10;         #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-e*x/r0;              #potential energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential energy is\",U,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "equilibrium distance is -2.25 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "U=6.4;                  #potential energy(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "r0=-e*x/U;              #equilibrium distance(m)\n",
+    "\n",
+    "\n",
+    "#Result\n",
+    "print \"equilibrium distance is\",r0*10**10,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "compressibility of the solid is -25.087 *10**14\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.76;             #madelung constant\n",
+    "n=0.5;                  #repulsive exponent\n",
+    "r0=4.1*10**-4;          #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "C=18*r0**4/(x*alpha*e**2*(n-1));     #compressibility of the solid\n",
+    "\n",
+    "#Result\n",
+    "print \"compressibility of the solid is\",round(C*10**-14,3),\"*10**14\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -6.45 eV\n",
+      "energy needed to form neutral atoms is -6.17 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.763;            #madelung constant\n",
+    "n=10.5;                 #repulsive exponent\n",
+    "r0=3.56*10**-10;        #equilibrium distance(m)\n",
+    "IE=3.89;                #ionisation energy(eV)\n",
+    "EA=-3.61;               #electron affinity(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "E=U+EA+IE;                            #energy needed to form neutral atoms\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U,2),\"eV\"\n",
+    "print \"energy needed to form neutral atoms is\",round(E,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 400"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -3.98 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.748;            #madelung constant\n",
+    "n=9;                 #repulsive exponent\n",
+    "r0=2.81*10**-10;        #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U/2,2),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3njJQNW.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3njJQNW.ipynb
new file mode 100644
index 00000000..283605cf
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3njJQNW.ipynb
@@ -0,0 +1,236 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 15: Superconductivity"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field at 3K is 0.006281 Tesla\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=0.0106;          #critical field at 0K(Tesla)\n",
+    "T=3;                #temperature(K)\n",
+    "Tc=4.7;             #temperature(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);     #critical field at 3K(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field at 3K is\",round(Hc,6),\"Tesla\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "temperature of superconductor is 1.701 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=5*10**5/(4*math.pi);          #critical field at 0K(Tesla)\n",
+    "Tc=2.69;                         #temperature(K)\n",
+    "Hc=3*10**5/(4*math.pi);          #critical field(Tesla)\n",
+    "\n",
+    "#Calculation\n",
+    "T=Tc*math.sqrt(1-(Hc/H0));       #temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"temperature of superconductor is\",round(T,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field is 4.3365 *10**4 A/m\n",
+      "critical current of the wire is 408 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=6.5*10**4;          #critical field at 0K(Tesla)\n",
+    "Tc=7.28;               #temperature(K)\n",
+    "T=4.2;                 #temperature(K)\n",
+    "r=1.5*10**-3;          #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);          #critical field(Tesla)\n",
+    "Ic=2*math.pi*r*Hc;            #critical current of the wire(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field is\",round(Hc/10**4,4),\"*10**4 A/m\"\n",
+    "print \"critical current of the wire is\",int(Ic),\"A\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical temperature is 4.124 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m1=199.5;             #isotopic mass\n",
+    "m2=205.4;             #change in mass \n",
+    "Tc1=4.185;            #temperature of mercury(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Tc2=Tc1*math.sqrt(m1/m2);     #critical temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical temperature is\",round(Tc2,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 444"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "superconducting transition temperature is 8.106 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "T1=3;            #temperature(K)\n",
+    "T2=8;            #temperature(K)\n",
+    "lamda1=39.6;     #penetration depth(nm)\n",
+    "lamda2=173;      #penetration depth(nm)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(lamda1/lamda2)**2;\n",
+    "Tc4=(T2**4-(x*T1**4))/(1-x);\n",
+    "Tc=Tc4**(1/4);   #superconducting transition temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"superconducting transition temperature is\",round(Tc,3),\"K\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3nqQG4m.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3nqQG4m.ipynb
new file mode 100644
index 00000000..a4871749
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_3nqQG4m.ipynb
@@ -0,0 +1,681 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 4: Matter Waves"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=3967;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h/(m*v);             #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",int(lamda*10**10),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of electron is 6 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=9.11*10**-31;            #mass of electron(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "lamda=5*10**-10;           #de-Broglie wavelength(m)\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*m*lamda**2*e);     #kinetic energy of electron(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of electron is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 3.97 *10**-6 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;                  #velocity of light(m/sec)\n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;             #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "v=c/30;             #velocity of proton(m/sec)\n",
+    "lamda=h/(m*v);     #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",round(lamda*10**14,2),\"*10**-6 angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of electron is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "V=150;          #potential difference(V)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=12.26/math.sqrt(V);     #de-Broglie wavelength of electron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of electron is\",int(lamda),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength is 1.23 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "V=100;                 #voltage(eV)  \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*e*V);    #de-Broglie wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of neutron is 0.99 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=4000;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/(m*v);             #de-Broglie wavelength of neutron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of neutron is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of kinetic energies of electron and proton is 1833\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mp=1.67*10**-27;            #mass of proton(kg)\n",
+    "me=9.11*10**-31;            #mass of electron(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "r=mp/me;                    #ratio of kinetic energies of electron and proton\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of kinetic energies of electron and proton is\",int(r)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of wavelengths is 32\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "E=1000;                #energy(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "r=math.sqrt(2*m/(e*E))*c;    #ratio of wavelengths\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of wavelengths is\",int(round(r))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of electron is 0.289 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "h=6.6*10**-34;         #planks constant(Js)\n",
+    "lamda=1.54*10**-10;    #wavelength of X-ray(m)\n",
+    "wf=1*10**-15;          #work function(J)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;           #energy of X-ray(J)\n",
+    "Ee=E-wf;               #energy of electron emitted(J)\n",
+    "lamda=h/math.sqrt(2*m*Ee);     #wavelength of electron(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of electron is\",round(lamda*10**10,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 161"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de broglie wavelength of proton is 1.537 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;         #mass of proton(kg)\n",
+    "h=6.6*10**-34;          #planks constant(Js)\n",
+    "T=400;                  #temperature(K)\n",
+    "k=1.38*10**-23;         #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*k*T);     #de broglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de broglie wavelength of proton is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "rest energy of electron is 8.19e-14 J\n",
+      "energy of proton is 8.19e-11 J\n",
+      "velocity of proton is 312902460.506 m/s\n",
+      "wavelength of electron is 1.27 *10**-5 angstrom\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.673*10**-27;        #mass of proton(kg)\n",
+    "m0=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "h=6.63*10**-34;         #planks constant(Js)\n",
+    "ke=1000;                #kinetic energy\n",
+    "\n",
+    "#Calculations\n",
+    "re=m0*c**2;             #rest energy of electron(J)\n",
+    "Ep=ke*re;               #energy of proton(J)\n",
+    "v=math.sqrt(2*Ep/m);     #velocity of proton(m/s)\n",
+    "lamda=h*10**10/(m*v);   #debroglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"rest energy of electron is\",re,\"J\"\n",
+    "print \"energy of proton is\",Ep,\"J\"\n",
+    "print \"velocity of proton is\",v,\"m/s\"\n",
+    "print \"wavelength of electron is\",round(lamda*10**5,2),\"*10**-5 angstrom\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 4.55 *10**7 m/s\n",
+      "kinetic energy is 5887 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "lamda=0.16*10**-10;    #debroglie wavelength of electron(m)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(lamda*m);         #velocity of electron(m/s)\n",
+    "KE=m*v**2/(2*e);       #kinetic energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-7,2),\"*10**7 m/s\"\n",
+    "print \"kinetic energy is\",int(KE),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 163"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "interplanar spacing of crystal is 1.78 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;       #mass of proton(kg)\n",
+    "h=6.62*10**-34;       #planks constant(Js)\n",
+    "T=300;                 #temperature(K)\n",
+    "k=1.38*10**-23;        #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "d=h*10**10/math.sqrt(2*m*k*T);     #interplanar spacing of crystal(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"interplanar spacing of crystal is\",round(d,2),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential is 605.16 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=0.5;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "V=(12.3/lamda)**2;    #potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential is\",V,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of gama ray photon is 19.89 *10**-16 J\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=1*10**-10;      #wavelength(m)\n",
+    "h=6.63*10**-34;       #planks constant(Js)\n",
+    "c=3*10**8;            #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "p=h/lamda;            #momentum(J-sec/m)\n",
+    "E=p*c;                #energy of gama ray photon(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of gama ray photon is\",E*10**16,\"*10**-16 J\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 16, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 2.2 *10**6 m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "h=6.6*10**-34;       #planks constant(Js)\n",
+    "m=9*10**-31;         #mass of electron(kg)\n",
+    "r=0.53*10**-10;      #radius of orbit(m)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(2*math.pi*r*m);   #velocity of electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-6,1),\"*10**6 m/sec\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_4GlnKNw.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_4GlnKNw.ipynb
new file mode 100644
index 00000000..449a8ffa
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_4GlnKNw.ipynb
@@ -0,0 +1,320 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 14: Magnetism"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 20 *10**9 A/m\n",
+      "flux density is 1.2818 *10**6 T\n",
+      "answer for flux density given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**12;                  #magnetic field intensity(A/m)\n",
+    "chi=20*10**-3;             #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #magnetisation(A/m)\n",
+    "B=mew0*(M+H);              #flux density(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M/10**9),\"*10**9 A/m\"\n",
+    "print \"flux density is\",round(B/10**6,4),\"*10**6 T\"\n",
+    "print \"answer for flux density given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 17725 A/m\n",
+      "answer for magnetisation given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**2;                  #magnetic field intensity(A/m)\n",
+    "B=0.0224;                  #flux density(T)\n",
+    "\n",
+    "#Calculations\n",
+    "M=(B/mew0)-H;              #magnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M),\"A/m\"\n",
+    "print \"answer for magnetisation given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "change in magnetic moment is 5.27 *10**-29 Am**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "r=5*10**-11;               #radius(m)\n",
+    "B=3;                       #flux density(T)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "mew=B*e**2*r**2/(4*m);     #change in magnetic moment(Am**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"change in magnetic moment is\",round(mew*10**29,2),\"*10**-29 Am**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "susceptibility is 0.8 *10**-4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=200;          #temperature(K)\n",
+    "T2=300;          #temperature(K)\n",
+    "chi1=1.2*10**-4; #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "chi2=T1*chi1/T2;    #susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"susceptibility is\",chi2*10**4,\"*10**-4\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "paramagnetisation is 3.6 *10**2 A/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "H=10**5;                  #magnetic field intensity(A/m)\n",
+    "chi=3.6*10**-3;            #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #paramagnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"paramagnetisation is\",M/10**2,\"*10**2 A/m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment is 5.655 *10**-24 Am**2\n",
+      "saturation magnetic induction is 6.5 *10**-4 T\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "mewB=9.27*10**-24;         \n",
+    "rho=8906;                  #density(kg/m**3)\n",
+    "N=6.023*10**23;            #avagadro number\n",
+    "W=58.7;                    #atomic weight\n",
+    "\n",
+    "#Calculations\n",
+    "mewM=0.61*mewB;            #magnetic moment(Am**2)\n",
+    "B=rho*N*mew0*mewM/W;       #saturation magnetic induction(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment is\",round(mewM*10**24,3),\"*10**-24 Am**2\"\n",
+    "print \"saturation magnetic induction is\",round(B*10**4,1),\"*10**-4 T\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 423"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "diamagnetic susceptibility is -8.249 *10**-8\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "R=0.5*10**-10;             #radius(m)\n",
+    "N=28*10**26;               #number of atoms\n",
+    "Z=2;                       #atomic number\n",
+    "\n",
+    "#Calculations\n",
+    "chi_dia=-mew0*Z*e**2*N*R**2/(6*m);    #diamagnetic susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"diamagnetic susceptibility is\",round(chi_dia*10**8,3),\"*10**-8\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_55ZHPE1.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_55ZHPE1.ipynb
new file mode 100644
index 00000000..444cec94
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_55ZHPE1.ipynb
@@ -0,0 +1,208 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 9: Nuclear Reactions"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value in nuclear reaction is -1.1898 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "N=14.003073;     #mass of N\n",
+    "O=16.99913;      #mass of O\n",
+    "H=1.007825;      #mass of H\n",
+    "He=4.002604;     #mass of He\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(N+He-(O+H))*m;     #Q value in nuclear reaction(MeV)    \n",
+    "\n",
+    "#Result\n",
+    "print \"Q value in nuclear reaction is\",round(Q,4),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "heat generated is 6.6 *10**6 KWH\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Li=7.01600;     #mass of Li\n",
+    "H=1.007825;     #mass of H\n",
+    "He=4.002604;    #mass of He\n",
+    "m=931; \n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "N=6.02*10**26;  #avagadro number\n",
+    "M=0.1;          #mass(kg)\n",
+    "x=1000*3600;\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Li+H-(He+He))*m*10**6*e;     #heat generated by Li(J)\n",
+    "mLi=Li/N;                       #mass of Li(kg) \n",
+    "H=Q*M/(x*mLi);                  #heat generated(KWH)\n",
+    "\n",
+    "#Result\n",
+    "print \"heat generated is\",round(H*10**-6,1),\"*10**6 KWH\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 300"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q-value for the reaction is 5.485 MeV\n",
+      "kinetic energy of Zn is 0.635 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Cu=62.929599;     #mass of Cu\n",
+    "H=2.014102;       #mass of H(amu)\n",
+    "n=1.008665;       #mass of n(amu)\n",
+    "Zn=63.929145;     #mass of Zn(amu)\n",
+    "m=931; \n",
+    "Kx=12;          #energy of deuterons(MeV)\n",
+    "Ky=16.85;       #kinetic energy of deuterons(MeV)\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(H+Cu-n-Zn)*m;     #Q-value for the reaction(MeV)\n",
+    "K=Q+Kx-Ky;           #kinetic energy of Zn(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q-value for the reaction is\",round(Q,3),\"MeV\"\n",
+    "print \"kinetic energy of Zn is\",round(K,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 301"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold kinetic energy is 5.378 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "P=1.007825;     #mass of P(amu)\n",
+    "H2=2.014102;    #mass of H2(amu)\n",
+    "H3=3.016049;    #mass of H3(amu)\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(P+H3-(2*H2))*m;         #Q-value(MeV)\n",
+    "Kth=-Q*(1+(P/H3));          #threshold kinetic energy(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold kinetic energy is\",round(Kth,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_7vAWWtf.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_7vAWWtf.ipynb
new file mode 100644
index 00000000..e9b7b5a0
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_7vAWWtf.ipynb
@@ -0,0 +1,250 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 12: X-ray Diffraction"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.0842 nm\n",
+      "maximum order of diffraction is 6\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=0.282;       #lattice spacing(nm)\n",
+    "theta=(8+(35/60))*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(nm)\n",
+    "n=2*d/lamda;                     #maximum order of diffraction\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"nm\"\n",
+    "print \"maximum order of diffraction is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "glancing angle for 1st order is 17 degrees 24 minutes\n",
+      "glancing angle for 2nd order is 36 degrees 44 minutes\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.209;       #lattice spacing(angstrom)\n",
+    "lamda=1.92;    #wavelength of X-rays(angstrom)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order \n",
+    "\n",
+    "#Calculation\n",
+    "theta1=math.asin(n1*lamda/(2*d))*180/math.pi;    #glancing angle for 1st order(degrees)\n",
+    "theta1d=int(theta1);                             #glancing angle for 1st order(degrees)  \n",
+    "theta1m=(theta1-theta1d)*60;                     #glancing angle for 1st order(minutes)\n",
+    "theta2=math.asin(n2*lamda/(2*d))*180/math.pi;    #glancing angle for 2nd order(degrees)\n",
+    "theta2d=int(theta2);                             #glancing angle for 2nd order(degrees)\n",
+    "theta2m=(theta2-theta2d)*60;                     #glancing angle for 2nd order(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"glancing angle for 1st order is\",theta1d,\"degrees\",int(theta1m),\"minutes\"\n",
+    "print \"glancing angle for 2nd order is\",theta2d,\"degrees\",int(theta2m),\"minutes\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 379"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.05;       #lattice spacing(angstrom)\n",
+    "theta=12*math.pi/180;     #glancing angle(radian)\n",
+    "n=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of line A is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "thetaA=30*math.pi/180;     #glancing angle(radian)\n",
+    "thetaB=60*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order\n",
+    "lamdaB=0.9;            #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Calculation\n",
+    "lamdaA=2*lamdaB*math.sin(thetaA)/math.sin(thetaB);    #wavelength of line A(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of line A is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.7853 angstrom\n",
+      "glancing angle for 2nd order is 18.2 degrees\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=2.51;       #lattice spacing(angstrom)\n",
+    "theta=9*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                    #order\n",
+    "n2=2;                    #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "theta=math.asin(n2*lamda/(2*d))*180/math.pi; #glancing angle for 2nd order(degrees)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"angstrom\"\n",
+    "print \"glancing angle for 2nd order is\",round(theta,1),\"degrees\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_8k98KXK.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_8k98KXK.ipynb
new file mode 100644
index 00000000..55a10563
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_8k98KXK.ipynb
@@ -0,0 +1,568 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 1: Atomic Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 55"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of emitted photon is 1.281 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=3;\n",
+    "n2=5;        #states\n",
+    "RH=1.0977*10**7;\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=RH*((1/n1**2)-(1/n2**2));\n",
+    "lamda=10**6/newbar;         #wavelength of emitted photon(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of emitted photon is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of principal quantum number of two orbits is 14 / 11\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "E1=1.21;\n",
+    "E2=1.96;        #energy of two orbits(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n1=math.sqrt(E2);\n",
+    "n2=math.sqrt(E1);       #ratio of principal quantum number of two orbits\n",
+    "n1=n1*10;\n",
+    "n2=n2*10;               #multiply and divide the ratio by 10\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of principal quantum number of two orbits is\",int(n1),\"/\",int(n2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment of proton is 5.041 *10**-27 Am**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "mp=1.672*10**-27;         #mass of electron(kg)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewp=e*h/(4*math.pi*mp);  #magnetic moment of proton(Am**2) \n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment of proton is\",round(mewp*10**27,3),\"*10**-27 Am**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "specific charge of electron is 1.7604 *10**11 coulomb/kg\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "mewB=9.274*10**-24;       #bohr magneton(amp m**2)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "ebym=mewB*4*math.pi/h;    #specific charge of electron(coulomb/kg)      \n",
+    "\n",
+    "#Result\n",
+    "print \"specific charge of electron is\",round(ebym/10**11,4),\"*10**11 coulomb/kg\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength separation is 0.3358 angstrom\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "B=1;                #flux density(Wb/m**2)\n",
+    "lamda=6000*10**-10; #wavelength(m)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "c=3*10**8;          #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "d_lamda=B*e*(lamda**2)/(4*math.pi*m*c);     #wavelength separation(m)\n",
+    "d_lamda=2*d_lamda*10**10;                   #wavelength separation(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength separation is\",round(d_lamda,4),\"angstrom\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of electron in 1st and 2nd orbit is -13.6 eV and -3.4 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        #states\n",
+    "\n",
+    "#Calculations\n",
+    "E1=-13.6/n1**2;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-13.6/n2**2;     #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of electron in 1st and 2nd orbit is\",E1,\"eV and\",E2,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "linear momentum is 2.107 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "lamda=0.5*10**-10;        #radius of 1st orbit(m)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "L=h/(2*math.pi*lamda);    #linear momentum(kg ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"linear momentum is\",round(L*10**24,3),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "state to which it is excited is 4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "E1=-13.6;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-12.75;    #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n=math.sqrt(-E1/(E2-E1));    #state to which it is excited\n",
+    "\n",
+    "#Result\n",
+    "print \"state to which it is excited is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "bohr magneton is 9.262 *10**-24 coulomb Js kg-1\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "h=6.62*10**-34;         #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewB=e*h/(4*math.pi*m);  #bohr magneton(coulomb Js kg-1) \n",
+    "\n",
+    "#Result\n",
+    "print \"bohr magneton is\",round(mewB*10**24,3),\"*10**-24 coulomb Js kg-1\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "component separation is 2.7983 *10**8 Hz\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "B=0.02;                 #magnetic field(T)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=e*B/(4*math.pi*m);    #component separation(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"component separation is\",round(delta_new/10**8,4),\"*10**8 Hz\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 61"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic flux density is 2.14 Tesla\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=10000*10**-10;    #wavelength(m)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "d_lamda=1*10**-10;      #wavelength separation(m)\n",
+    "\n",
+    "#Calculations\n",
+    "B=d_lamda*4*math.pi*m*c/(e*lamda**2);      #magnetic flux density(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic flux density is\",round(B,2),\"Tesla\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 19, Page number 66"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "separation is 0.33 angstrom\n",
+      "wavelength of three components is 4226 angstrom 4226.33 angstrom 4226.666 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=4226;             #wavelength(angstrom)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "B=4;                    #magnetic field(Wb/m**2)\n",
+    "\n",
+    "#Calculations\n",
+    "dnew=B*e/(4*math.pi*m);    \n",
+    "dlamda=lamda**2*dnew*10**-10/c;      #separation(angstrom)\n",
+    "dlamda1=lamda+dlamda;\n",
+    "dlamda2=dlamda1+dlamda;    #wavelength of three components(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"separation is\",round(dlamda,2),\"angstrom\"\n",
+    "print \"wavelength of three components is\",lamda,\"angstrom\",round(dlamda1,2),\"angstrom\",round(dlamda2,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 21, Page number 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of elements would be 110\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        \n",
+    "n3=3;\n",
+    "n4=4;\n",
+    "n5=5;\n",
+    "\n",
+    "#Calculations\n",
+    "e1=2*n1**2;     #maximum number of electrons in 1st orbit\n",
+    "e2=2*n2**2;     #maximum number of electrons in 2nd orbit\n",
+    "e3=2*n3**2;     #maximum number of electrons in 3rd orbit\n",
+    "e4=2*n4**2;     #maximum number of electrons in 4th orbit\n",
+    "e5=2*n5**2;     #maximum number of electrons in 5th orbit\n",
+    "e=e1+e2+e3+e4+e5;      #number of elements\n",
+    "\n",
+    "#Result\n",
+    "print \"number of elements would be\",e"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_9epeI5v.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_9epeI5v.ipynb
new file mode 100644
index 00000000..ecefb615
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_9epeI5v.ipynb
@@ -0,0 +1,210 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 8: Alpha and Beta Decays"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 282"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of beta article is 0.8624 c\n",
+      "mass of beta particle is 1.98 m0\n",
+      "flux density is 0.029106 weber/m**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;     #charge(coulomb)\n",
+    "Ek=0.5*10**6;      #kinetic energy(eV)\n",
+    "m0=9.11*10**-31;   #mass(kg)\n",
+    "c=3*10**8;         #velocity of light(m/s)\n",
+    "r=0.1;             #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(Ek*e/(m0*c**2))+1;\n",
+    "y=1-(1/x)**2;\n",
+    "v=c*math.sqrt(y);     #velocity of beta article(m/s)\n",
+    "m=m0/math.sqrt(1-(v/c)**2);     #mass of beta particle(kg)\n",
+    "B=m*v/(e*r);                    #flux density(weber/m**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of beta article is\",round(v/c,4),\"c\"\n",
+    "print \"mass of beta particle is\",round(m/m0,2),\"m0\"\n",
+    "print \"flux density is\",round(B,6),\"weber/m**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of alpha particle is 4.782 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A=226;       #atomic weight\n",
+    "Ra=226.02540;     #mass of Ra\n",
+    "Rn=222.017571;    #mass of Rn\n",
+    "He=4.002603;      #mass of He\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ra-Rn-He)*m;   \n",
+    "kalpha=(A-4)*Q/A;    #kinetic energy of alpha particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of alpha particle is\",round(kalpha,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum kinetic energy of electrons is 4.548 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ne=22.99465;     #mass of Ne\n",
+    "Na=22.989768;    #mass of Na\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ne-Na)*m;     #maximum kinetic energy of electrons(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum kinetic energy of electrons is\",round(Q,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 284"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value of 1st decay is 0.482 MeV\n",
+      "Q value of 2nd decay is 1.504 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "K=39.963999;     #mass of K\n",
+    "Ca=39.962591;    #mass of Ca\n",
+    "Ar=39.962384;    #mass of Ar\n",
+    "me=0.000549;     #mass of electron  \n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q1=(K-Ar-(2*me))*m;   #Q value of 1st decay(MeV)\n",
+    "Q2=(K-Ar)*m;      #Q value of 2nd decay(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q value of 1st decay is\",round(Q1,3),\"MeV\"\n",
+    "print \"Q value of 2nd decay is\",round(Q2,3),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_CEeTHUJ.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_CEeTHUJ.ipynb
new file mode 100644
index 00000000..fd167244
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_CEeTHUJ.ipynb
@@ -0,0 +1,304 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 6: Schrodinger Wave Mechanics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 228"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy levels are 38 eV 150 eV 339 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "a=10**-10;            #width(m)\n",
+    "h=6.62*10**-34;       #planck's constant\n",
+    "n1=1;\n",
+    "n2=2;\n",
+    "n3=3;\n",
+    "\n",
+    "#Calculation\n",
+    "Ex=h**2/(8*e*m*a**2);  #energy(eV)\n",
+    "E1=Ex*n1**2;         #energy at 1st level(eV)\n",
+    "E2=Ex*n2**2;         #energy at 2nd level(eV)\n",
+    "E3=Ex*n3**2;         #energy at 3rd level(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy levels are\",int(round(E1)),\"eV\",int(round(E2)),\"eV\",int(round(E3)),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of finding the particle is 0.133\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "deltax=1*10**-10;        #width\n",
+    "a=15*10**-10;            #width(m)\n",
+    "\n",
+    "#Calculation\n",
+    "W=2*deltax/a;            #probability of finding the particle\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of finding the particle is\",round(W,3)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of transmission of electron is 0.5\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=1;          #energy(eV)\n",
+    "V0=2;         #voltage(eV)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "chi=1.05*10**-34;     \n",
+    "a=2*10**-10;          #potential barrier\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(2*m*(V0-E)*e);\n",
+    "y=16*E*(1-(E/V0))/V0;\n",
+    "T=y*math.exp(-2*a*x/chi);     #probability of transmission of electron\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of transmission of electron is\",round(T,1)\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 230"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 32,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons reflected is 0.38\n",
+      "fraction of electrons transmitted is 0.62\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.080*10**-19;          #energy(eV)\n",
+    "E_V0=0.016*10**-19;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "R=(x-y)/(x+y);       #fraction of electrons reflected\n",
+    "T=1-R;                    #fraction of electrons transmitted\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons reflected is\",round(R,2)\n",
+    "print \"fraction of electrons transmitted is\",round(T,2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 231"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 37,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons transmitted is 0.4998\n",
+      "fraction of electrons reflected is 0.5002\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.34;          #energy(eV)\n",
+    "E_V0=0.01;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "T=4*x*y/(x+y)**2;       #fraction of electrons transmitted \n",
+    "R=1-T;                  #fraction of electrons reflected\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons transmitted is\",round(T,4)\n",
+    "print \"fraction of electrons reflected is\",round(R,4)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 232"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 50,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "transmission coefficient is 3.27 *10**-9\n",
+      "transmission coefficient in 1st case is 7.62 *10**-8\n",
+      "transmission coefficient in 2nd case is 1.51 *10**-15\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "E1=1*e;         #energy(J)\n",
+    "E2=2*e;         #energy(J)\n",
+    "V0=5*e;         #voltage(J)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "chi=1.054*10**-34;     \n",
+    "a1=10*10**-10;         #potential barrier(m)\n",
+    "a2=20*10**-10;         #potential barrier(m)\n",
+    "\n",
+    "#Calculation\n",
+    "beta1=math.sqrt(2*m*(V0-E1)/(chi**2));\n",
+    "y1=16*E1*((V0-E1)/(V0**2));\n",
+    "T1=y1*math.exp(-2*a1*beta1);     #transmission coefficient\n",
+    "beta2=math.sqrt(2*m*(V0-E2)/(chi**2));\n",
+    "y2=16*E2*((V0-E2)/(V0**2));\n",
+    "T2=y2*math.exp(-2*a1*beta2);     #transmission coefficient in 1st case\n",
+    "T3=y2*math.exp(-2*a2*beta2);     #transmission coefficient in 2nd case\n",
+    "\n",
+    "#Result\n",
+    "print \"transmission coefficient is\",round(T1*10**9,2),\"*10**-9\"\n",
+    "print \"transmission coefficient in 1st case is\",round(T2*10**8,2),\"*10**-8\"\n",
+    "print \"transmission coefficient in 2nd case is\",round(T3*10**15,2),\"*10**-15\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_E1eRmp6.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_E1eRmp6.ipynb
new file mode 100644
index 00000000..444cec94
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_E1eRmp6.ipynb
@@ -0,0 +1,208 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 9: Nuclear Reactions"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value in nuclear reaction is -1.1898 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "N=14.003073;     #mass of N\n",
+    "O=16.99913;      #mass of O\n",
+    "H=1.007825;      #mass of H\n",
+    "He=4.002604;     #mass of He\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(N+He-(O+H))*m;     #Q value in nuclear reaction(MeV)    \n",
+    "\n",
+    "#Result\n",
+    "print \"Q value in nuclear reaction is\",round(Q,4),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "heat generated is 6.6 *10**6 KWH\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Li=7.01600;     #mass of Li\n",
+    "H=1.007825;     #mass of H\n",
+    "He=4.002604;    #mass of He\n",
+    "m=931; \n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "N=6.02*10**26;  #avagadro number\n",
+    "M=0.1;          #mass(kg)\n",
+    "x=1000*3600;\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Li+H-(He+He))*m*10**6*e;     #heat generated by Li(J)\n",
+    "mLi=Li/N;                       #mass of Li(kg) \n",
+    "H=Q*M/(x*mLi);                  #heat generated(KWH)\n",
+    "\n",
+    "#Result\n",
+    "print \"heat generated is\",round(H*10**-6,1),\"*10**6 KWH\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 300"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q-value for the reaction is 5.485 MeV\n",
+      "kinetic energy of Zn is 0.635 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Cu=62.929599;     #mass of Cu\n",
+    "H=2.014102;       #mass of H(amu)\n",
+    "n=1.008665;       #mass of n(amu)\n",
+    "Zn=63.929145;     #mass of Zn(amu)\n",
+    "m=931; \n",
+    "Kx=12;          #energy of deuterons(MeV)\n",
+    "Ky=16.85;       #kinetic energy of deuterons(MeV)\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(H+Cu-n-Zn)*m;     #Q-value for the reaction(MeV)\n",
+    "K=Q+Kx-Ky;           #kinetic energy of Zn(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q-value for the reaction is\",round(Q,3),\"MeV\"\n",
+    "print \"kinetic energy of Zn is\",round(K,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 301"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold kinetic energy is 5.378 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "P=1.007825;     #mass of P(amu)\n",
+    "H2=2.014102;    #mass of H2(amu)\n",
+    "H3=3.016049;    #mass of H3(amu)\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(P+H3-(2*H2))*m;         #Q-value(MeV)\n",
+    "Kth=-Q*(1+(P/H3));          #threshold kinetic energy(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold kinetic energy is\",round(Kth,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_GQ8CWIs.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_GQ8CWIs.ipynb
new file mode 100644
index 00000000..444cec94
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_GQ8CWIs.ipynb
@@ -0,0 +1,208 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 9: Nuclear Reactions"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value in nuclear reaction is -1.1898 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "N=14.003073;     #mass of N\n",
+    "O=16.99913;      #mass of O\n",
+    "H=1.007825;      #mass of H\n",
+    "He=4.002604;     #mass of He\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(N+He-(O+H))*m;     #Q value in nuclear reaction(MeV)    \n",
+    "\n",
+    "#Result\n",
+    "print \"Q value in nuclear reaction is\",round(Q,4),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 299"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "heat generated is 6.6 *10**6 KWH\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Li=7.01600;     #mass of Li\n",
+    "H=1.007825;     #mass of H\n",
+    "He=4.002604;    #mass of He\n",
+    "m=931; \n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "N=6.02*10**26;  #avagadro number\n",
+    "M=0.1;          #mass(kg)\n",
+    "x=1000*3600;\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Li+H-(He+He))*m*10**6*e;     #heat generated by Li(J)\n",
+    "mLi=Li/N;                       #mass of Li(kg) \n",
+    "H=Q*M/(x*mLi);                  #heat generated(KWH)\n",
+    "\n",
+    "#Result\n",
+    "print \"heat generated is\",round(H*10**-6,1),\"*10**6 KWH\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 300"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q-value for the reaction is 5.485 MeV\n",
+      "kinetic energy of Zn is 0.635 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Cu=62.929599;     #mass of Cu\n",
+    "H=2.014102;       #mass of H(amu)\n",
+    "n=1.008665;       #mass of n(amu)\n",
+    "Zn=63.929145;     #mass of Zn(amu)\n",
+    "m=931; \n",
+    "Kx=12;          #energy of deuterons(MeV)\n",
+    "Ky=16.85;       #kinetic energy of deuterons(MeV)\n",
+    "\n",
+    "#Calculation\n",
+    "Q=(H+Cu-n-Zn)*m;     #Q-value for the reaction(MeV)\n",
+    "K=Q+Kx-Ky;           #kinetic energy of Zn(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q-value for the reaction is\",round(Q,3),\"MeV\"\n",
+    "print \"kinetic energy of Zn is\",round(K,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 301"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold kinetic energy is 5.378 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "P=1.007825;     #mass of P(amu)\n",
+    "H2=2.014102;    #mass of H2(amu)\n",
+    "H3=3.016049;    #mass of H3(amu)\n",
+    "m=931; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(P+H3-(2*H2))*m;         #Q-value(MeV)\n",
+    "Kth=-Q*(1+(P/H3));          #threshold kinetic energy(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold kinetic energy is\",round(Kth,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_HEd5C4N.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_HEd5C4N.ipynb
new file mode 100644
index 00000000..3725056f
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_HEd5C4N.ipynb
@@ -0,0 +1,243 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 13: Bonding In Crystals"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential energy is -5.76 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "r0=2.5*10**-10;         #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-e*x/r0;              #potential energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential energy is\",U,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "equilibrium distance is -2.25 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "U=6.4;                  #potential energy(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "r0=-e*x/U;              #equilibrium distance(m)\n",
+    "\n",
+    "\n",
+    "#Result\n",
+    "print \"equilibrium distance is\",r0*10**10,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "compressibility of the solid is -25.087 *10**14\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.76;             #madelung constant\n",
+    "n=0.5;                  #repulsive exponent\n",
+    "r0=4.1*10**-4;          #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "C=18*r0**4/(x*alpha*e**2*(n-1));     #compressibility of the solid\n",
+    "\n",
+    "#Result\n",
+    "print \"compressibility of the solid is\",round(C*10**-14,3),\"*10**14\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -6.45 eV\n",
+      "energy needed to form neutral atoms is -6.17 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.763;            #madelung constant\n",
+    "n=10.5;                 #repulsive exponent\n",
+    "r0=3.56*10**-10;        #equilibrium distance(m)\n",
+    "IE=3.89;                #ionisation energy(eV)\n",
+    "EA=-3.61;               #electron affinity(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "E=U+EA+IE;                            #energy needed to form neutral atoms\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U,2),\"eV\"\n",
+    "print \"energy needed to form neutral atoms is\",round(E,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 400"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -3.98 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.748;            #madelung constant\n",
+    "n=9;                 #repulsive exponent\n",
+    "r0=2.81*10**-10;        #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U/2,2),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_IlcYN96.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_IlcYN96.ipynb
new file mode 100644
index 00000000..4f050408
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_IlcYN96.ipynb
@@ -0,0 +1,244 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 10: Nuclear Detectors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "current produced is 1.829 *10**-13 amp\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "n=10;               #number of particles\n",
+    "E=4*10**6;          #energy of alpha particle(eV)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "N=E*n/E1;             #number of ion pairs\n",
+    "q=N*e;                #current produced(amp)\n",
+    "\n",
+    "#Result\n",
+    "print \"current produced is\",round(q*10**13,3),\"*10**-13 amp\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of ion pairs required is 6.25 *10**5\n",
+      "energy of alpha-particles is 21.875 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "v=4;                #voltage sensitivity(div/volt)\n",
+    "d=0.8;              #number of divisions\n",
+    "C=0.5*10**-12;      #capacitance(F)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "V=d/v;              #voltage(V)\n",
+    "q=C*V;              #current(C)\n",
+    "n=q/e;              #number of ion pairs required\n",
+    "E=n*E1/10**6;       #energy of alpha-particles(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"number of ion pairs required is\",n/10**5,\"*10**5\"\n",
+    "print \"energy of alpha-particles is\",E,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 323"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum radial field is 1.89 *10**6 volts/meter\n",
+      "counter will last for 3.7 years\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "V=1000;              #voltage(V)\n",
+    "r=0.0001;            #radius(m)\n",
+    "b=2*10**-2;          #diameter(m)\n",
+    "a=10**-4;\n",
+    "n=10**9;             #number of counts\n",
+    "\n",
+    "#Calculation\n",
+    "Emax=V/(r*math.log(b/a));    #maximum radial field(volts/meter)\n",
+    "N=n/(50*30*60*3000);         #counter will last for(years)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum radial field is\",round(Emax/10**6,2),\"*10**6 volts/meter\"\n",
+    "print \"counter will last for\",round(N,1),\"years\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 324"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of the particle is 1500 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "r=2;               #radius(m)\n",
+    "B=2.5;             #flux density(Wb/m**2)\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "c=3*10**8;         #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculation\n",
+    "E=B*q*r*c*10**-6/q;     #energy of the particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of the particle is\",int(E),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 325"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average current in the circuit is 1.6e-11 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "cr=600;            #counting rate(counts/minute)\n",
+    "e=10**7;           #number of electrons per discharge\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "t=60;              #number of seconds\n",
+    "\n",
+    "#Calculation\n",
+    "n=cr*e;            #number of electrons in 1 minute\n",
+    "q=n*q/t;           #average current in the circuit(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"average current in the circuit is\",q,\"A\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_Jn2jAxR.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_Jn2jAxR.ipynb
new file mode 100644
index 00000000..1d50ed48
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_Jn2jAxR.ipynb
@@ -0,0 +1,384 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 11: Crystal Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 4 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "c=1/4;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 3 2 0 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "x=float(\"inf\");\n",
+    "c=1/x;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "lcm=lcm(1/a,1/b);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 358"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 3 2 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=1/2;\n",
+    "c=1/3;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 359"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding intercept on Y-axis and Z-axis are 0.8 angstrom and 0.65 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1.1;\n",
+    "b=1.2;\n",
+    "c=1.3;     #intercepts along the three axes(angstrom)\n",
+    "h=2;\n",
+    "k=3;\n",
+    "l=4;       #miller indices of plane\n",
+    "\n",
+    "#Calculations\n",
+    "l1=a*h/h;\n",
+    "l2=b*h/k;    #corresponding intercept on Y-axis(angstrom)\n",
+    "l3=c*h/l;    #corresponding intercept on Z-axis(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding intercept on Y-axis and Z-axis are\",l2,\"angstrom and\",l3,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 -2 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=-1/3;\n",
+    "c=1/2;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 3.61 angstrom\n",
+      "distance between two nearest copper atoms is 2.55 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=4;        #number of molecules per unit cell\n",
+    "M=63.5;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=8.96*10**3;    #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "a=round(a*10**10,2);        #lattice constant(angstrom) \n",
+    "d=a/math.sqrt(2);           #distance between two nearest copper atoms(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",a,\"angstrom\"\n",
+    "print \"distance between two nearest copper atoms is\",round(d,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 361"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 2.8687 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=2;        #number of molecules per unit cell\n",
+    "M=55.85;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=7860;          #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",round(a*10**10,4),\"angstrom\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_L5T0xXa.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_L5T0xXa.ipynb
new file mode 100644
index 00000000..283605cf
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_L5T0xXa.ipynb
@@ -0,0 +1,236 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 15: Superconductivity"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field at 3K is 0.006281 Tesla\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=0.0106;          #critical field at 0K(Tesla)\n",
+    "T=3;                #temperature(K)\n",
+    "Tc=4.7;             #temperature(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);     #critical field at 3K(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field at 3K is\",round(Hc,6),\"Tesla\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "temperature of superconductor is 1.701 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=5*10**5/(4*math.pi);          #critical field at 0K(Tesla)\n",
+    "Tc=2.69;                         #temperature(K)\n",
+    "Hc=3*10**5/(4*math.pi);          #critical field(Tesla)\n",
+    "\n",
+    "#Calculation\n",
+    "T=Tc*math.sqrt(1-(Hc/H0));       #temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"temperature of superconductor is\",round(T,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field is 4.3365 *10**4 A/m\n",
+      "critical current of the wire is 408 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=6.5*10**4;          #critical field at 0K(Tesla)\n",
+    "Tc=7.28;               #temperature(K)\n",
+    "T=4.2;                 #temperature(K)\n",
+    "r=1.5*10**-3;          #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);          #critical field(Tesla)\n",
+    "Ic=2*math.pi*r*Hc;            #critical current of the wire(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field is\",round(Hc/10**4,4),\"*10**4 A/m\"\n",
+    "print \"critical current of the wire is\",int(Ic),\"A\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical temperature is 4.124 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m1=199.5;             #isotopic mass\n",
+    "m2=205.4;             #change in mass \n",
+    "Tc1=4.185;            #temperature of mercury(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Tc2=Tc1*math.sqrt(m1/m2);     #critical temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical temperature is\",round(Tc2,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 444"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "superconducting transition temperature is 8.106 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "T1=3;            #temperature(K)\n",
+    "T2=8;            #temperature(K)\n",
+    "lamda1=39.6;     #penetration depth(nm)\n",
+    "lamda2=173;      #penetration depth(nm)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(lamda1/lamda2)**2;\n",
+    "Tc4=(T2**4-(x*T1**4))/(1-x);\n",
+    "Tc=Tc4**(1/4);   #superconducting transition temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"superconducting transition temperature is\",round(Tc,3),\"K\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_NHRNirZ.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_NHRNirZ.ipynb
new file mode 100644
index 00000000..72f70169
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_NHRNirZ.ipynb
@@ -0,0 +1,540 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 3: Inadequacy of Classical Physics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum energy of photoelectron is 3.038 *10**-19 J\n",
+      "maximum velocity of electron is 8.17 *10**5 ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=1700*10**-10;       #wavelength(m)\n",
+    "lamda0=2300*10**-10;      #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "KE=h*c*((1/lamda)-(1/lamda0));       #maximum energy of photoelectron(J)\n",
+    "vmax=math.sqrt(2*KE/me);             #maximum velocity of electron(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum energy of photoelectron is\",round(KE*10**19,3),\"*10**-19 J\"\n",
+    "print \"maximum velocity of electron is\",round(vmax/10**5,2),\"*10**5 ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold wavelength is 5380 angstrom\n",
+      "since wavelength of orange light is more, photoelectric effect doesn't take place\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=2.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=6850;               #wavelength of orange light(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda0=h*c/W;             #threshold wavelength(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold wavelength is\",int(lamda0*10**10),\"angstrom\"\n",
+    "print \"since wavelength of orange light is more, photoelectric effect doesn't take place\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "retarding potential is 1.175 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=1.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "new=6*10**14;             #frequency(Hertz)\n",
+    "\n",
+    "#Calculations\n",
+    "V0=((h*new)-W)/e;         #retarding potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"retarding potential is\",V0,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "work function is 1.28 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=3*10**-7;           #wavelength(m)\n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "v=1*10**6;                #velocity(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "W=(h*c/lamda)-(me*v**2/2);      #work function(J)\n",
+    "W=W/e;                          #work function(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"work function is\",round(W,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "photoelectric current is 1.86 micro ampere\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=4600*10**-10;       #wavelength(m)\n",
+    "qe=0.5;                   #efficiency(%)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;              #energy(J)\n",
+    "n=10**-3/E;               #number of photons/second\n",
+    "i=n*qe*e*10**6/100;       #photoelectric current(micro ampere)\n",
+    "\n",
+    "#Result\n",
+    "print \"photoelectric current is\",round(i,2),\"micro ampere\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 130"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "planck's constant is 6.61 *10**-34 joule second\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=3*10**-19;             #temperature(J)\n",
+    "T2=1*10**-19;             #temperature(J)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda1=3350;              #wavelength(m)\n",
+    "lamda2=5060;              #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "x=10**10*((1/lamda1)-(1/lamda2));\n",
+    "h=(T1-T2)/(c*x);          #planck's constant(joule second)\n",
+    "\n",
+    "#Result\n",
+    "print \"planck's constant is\",round(h*10**34,2),\"*10**-34 joule second\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 131"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 3.0121 angstrom\n",
+      "energy of recoil electron is 2.66 *10**-18 joule\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=60*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(angstrom)\n",
+    "lamda_dash=3.058;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "lamda_dash=round(lamda_dash*10**10,4)*10**-10;     #wavelength of scattered radiation(m)\n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash*10**10,\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**18,2),\"*10**-18 joule\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 132"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 2.003 angstrom\n",
+      "velocity of recoil electron is 0.0188 *10**8 ms-1\n",
+      "answer for velocity given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=30*math.pi/180;    #angle(radian)\n",
+    "lamda=2*10**-10;         #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=1+(E/(m0*c**2));\n",
+    "v=c*math.sqrt(1-((1/x)**2));                       #velocity of recoil electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"velocity of recoil electron is\",round(v/10**8,4),\"*10**8 ms-1\"\n",
+    "print \"answer for velocity given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 133"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 49,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered photon is 3.024 angstrom\n",
+      "energy of recoil electron is 0.5 *10**-17 joules\n",
+      "direction of recoil electron is 44 degrees 46 minutes\n",
+      "answer for angle given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(m)   \n",
+    "\n",
+    "#Calculations\n",
+    "lamda_dash=lamda+(h*(1-math.cos(theta))/(m0*c));   #wavelength of scattered photon(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=h/(lamda*m0*c);\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered photon is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**17,1),\"*10**-17 joules\"\n",
+    "print \"direction of recoil electron is\",int(phi),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for angle given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 134"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 51,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of scattered photon is 0.226 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=180*math.pi/180;   #angle(radian)\n",
+    "E=1.96*10**6*e;          #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=2*h/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;   #wavelength of scattered photon(m)    \n",
+    "Edash=h*c/(e*lamda_dash);       #energy of scattered photon(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of scattered photon is\",round(Edash/10**6,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 135"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 65,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 4.9e-12 m\n",
+      "energy of recoil electron is 3.9592 *10**-14 Joules\n",
+      "direction of recoil electron is 27 degrees 47 minutes\n",
+      "answer for energy and direction of recoil electron and given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.6*10**-34;           #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "E=500*10**3*e;           #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=h*(1-math.cos(theta))/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;           #wavelength of scattered radiation(m) \n",
+    "lamda_dash=round(lamda_dash*10**12,1)*10**-12;   #wavelength of scattered radiation(m) \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));       #energy of recoil electron(J)\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash,\"m\"\n",
+    "print \"energy of recoil electron is\",round(E*10**14,4),\"*10**-14 Joules\"\n",
+    "print \"direction of recoil electron is\",int(round(phi)),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for energy and direction of recoil electron and given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PE2KT6W.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PE2KT6W.ipynb
new file mode 100644
index 00000000..e9b7b5a0
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PE2KT6W.ipynb
@@ -0,0 +1,250 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 12: X-ray Diffraction"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.0842 nm\n",
+      "maximum order of diffraction is 6\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=0.282;       #lattice spacing(nm)\n",
+    "theta=(8+(35/60))*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(nm)\n",
+    "n=2*d/lamda;                     #maximum order of diffraction\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"nm\"\n",
+    "print \"maximum order of diffraction is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "glancing angle for 1st order is 17 degrees 24 minutes\n",
+      "glancing angle for 2nd order is 36 degrees 44 minutes\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.209;       #lattice spacing(angstrom)\n",
+    "lamda=1.92;    #wavelength of X-rays(angstrom)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order \n",
+    "\n",
+    "#Calculation\n",
+    "theta1=math.asin(n1*lamda/(2*d))*180/math.pi;    #glancing angle for 1st order(degrees)\n",
+    "theta1d=int(theta1);                             #glancing angle for 1st order(degrees)  \n",
+    "theta1m=(theta1-theta1d)*60;                     #glancing angle for 1st order(minutes)\n",
+    "theta2=math.asin(n2*lamda/(2*d))*180/math.pi;    #glancing angle for 2nd order(degrees)\n",
+    "theta2d=int(theta2);                             #glancing angle for 2nd order(degrees)\n",
+    "theta2m=(theta2-theta2d)*60;                     #glancing angle for 2nd order(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"glancing angle for 1st order is\",theta1d,\"degrees\",int(theta1m),\"minutes\"\n",
+    "print \"glancing angle for 2nd order is\",theta2d,\"degrees\",int(theta2m),\"minutes\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 379"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.05;       #lattice spacing(angstrom)\n",
+    "theta=12*math.pi/180;     #glancing angle(radian)\n",
+    "n=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of line A is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "thetaA=30*math.pi/180;     #glancing angle(radian)\n",
+    "thetaB=60*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order\n",
+    "lamdaB=0.9;            #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Calculation\n",
+    "lamdaA=2*lamdaB*math.sin(thetaA)/math.sin(thetaB);    #wavelength of line A(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of line A is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.7853 angstrom\n",
+      "glancing angle for 2nd order is 18.2 degrees\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=2.51;       #lattice spacing(angstrom)\n",
+    "theta=9*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                    #order\n",
+    "n2=2;                    #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "theta=math.asin(n2*lamda/(2*d))*180/math.pi; #glancing angle for 2nd order(degrees)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"angstrom\"\n",
+    "print \"glancing angle for 2nd order is\",round(theta,1),\"degrees\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PKCP8ZY.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PKCP8ZY.ipynb
new file mode 100644
index 00000000..55a10563
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PKCP8ZY.ipynb
@@ -0,0 +1,568 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 1: Atomic Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 55"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of emitted photon is 1.281 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=3;\n",
+    "n2=5;        #states\n",
+    "RH=1.0977*10**7;\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=RH*((1/n1**2)-(1/n2**2));\n",
+    "lamda=10**6/newbar;         #wavelength of emitted photon(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of emitted photon is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of principal quantum number of two orbits is 14 / 11\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "E1=1.21;\n",
+    "E2=1.96;        #energy of two orbits(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n1=math.sqrt(E2);\n",
+    "n2=math.sqrt(E1);       #ratio of principal quantum number of two orbits\n",
+    "n1=n1*10;\n",
+    "n2=n2*10;               #multiply and divide the ratio by 10\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of principal quantum number of two orbits is\",int(n1),\"/\",int(n2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment of proton is 5.041 *10**-27 Am**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "mp=1.672*10**-27;         #mass of electron(kg)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewp=e*h/(4*math.pi*mp);  #magnetic moment of proton(Am**2) \n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment of proton is\",round(mewp*10**27,3),\"*10**-27 Am**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "specific charge of electron is 1.7604 *10**11 coulomb/kg\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "mewB=9.274*10**-24;       #bohr magneton(amp m**2)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "ebym=mewB*4*math.pi/h;    #specific charge of electron(coulomb/kg)      \n",
+    "\n",
+    "#Result\n",
+    "print \"specific charge of electron is\",round(ebym/10**11,4),\"*10**11 coulomb/kg\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength separation is 0.3358 angstrom\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "B=1;                #flux density(Wb/m**2)\n",
+    "lamda=6000*10**-10; #wavelength(m)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "c=3*10**8;          #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "d_lamda=B*e*(lamda**2)/(4*math.pi*m*c);     #wavelength separation(m)\n",
+    "d_lamda=2*d_lamda*10**10;                   #wavelength separation(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength separation is\",round(d_lamda,4),\"angstrom\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 57"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of electron in 1st and 2nd orbit is -13.6 eV and -3.4 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        #states\n",
+    "\n",
+    "#Calculations\n",
+    "E1=-13.6/n1**2;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-13.6/n2**2;     #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of electron in 1st and 2nd orbit is\",E1,\"eV and\",E2,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "linear momentum is 2.107 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "lamda=0.5*10**-10;        #radius of 1st orbit(m)\n",
+    "h=6.62*10**-34;           #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "L=h/(2*math.pi*lamda);    #linear momentum(kg ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"linear momentum is\",round(L*10**24,3),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 58"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "state to which it is excited is 4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "E1=-13.6;     #energy of electron in 1st orbit(eV)\n",
+    "E2=-12.75;    #energy of electron in 2nd orbit(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "n=math.sqrt(-E1/(E2-E1));    #state to which it is excited\n",
+    "\n",
+    "#Result\n",
+    "print \"state to which it is excited is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "bohr magneton is 9.262 *10**-24 coulomb Js kg-1\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "h=6.62*10**-34;         #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "mewB=e*h/(4*math.pi*m);  #bohr magneton(coulomb Js kg-1) \n",
+    "\n",
+    "#Result\n",
+    "print \"bohr magneton is\",round(mewB*10**24,3),\"*10**-24 coulomb Js kg-1\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "component separation is 2.7983 *10**8 Hz\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "B=0.02;                 #magnetic field(T)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=e*B/(4*math.pi*m);    #component separation(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"component separation is\",round(delta_new/10**8,4),\"*10**8 Hz\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 61"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic flux density is 2.14 Tesla\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=10000*10**-10;    #wavelength(m)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "d_lamda=1*10**-10;      #wavelength separation(m)\n",
+    "\n",
+    "#Calculations\n",
+    "B=d_lamda*4*math.pi*m*c/(e*lamda**2);      #magnetic flux density(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic flux density is\",round(B,2),\"Tesla\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 19, Page number 66"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "separation is 0.33 angstrom\n",
+      "wavelength of three components is 4226 angstrom 4226.33 angstrom 4226.666 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "m=9.1*10**-31;          #mass of electron(kg)\n",
+    "lamda=4226;             #wavelength(angstrom)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "B=4;                    #magnetic field(Wb/m**2)\n",
+    "\n",
+    "#Calculations\n",
+    "dnew=B*e/(4*math.pi*m);    \n",
+    "dlamda=lamda**2*dnew*10**-10/c;      #separation(angstrom)\n",
+    "dlamda1=lamda+dlamda;\n",
+    "dlamda2=dlamda1+dlamda;    #wavelength of three components(Hz)\n",
+    "\n",
+    "#Result\n",
+    "print \"separation is\",round(dlamda,2),\"angstrom\"\n",
+    "print \"wavelength of three components is\",lamda,\"angstrom\",round(dlamda1,2),\"angstrom\",round(dlamda2,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 21, Page number 68"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of elements would be 110\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n1=1;\n",
+    "n2=2;        \n",
+    "n3=3;\n",
+    "n4=4;\n",
+    "n5=5;\n",
+    "\n",
+    "#Calculations\n",
+    "e1=2*n1**2;     #maximum number of electrons in 1st orbit\n",
+    "e2=2*n2**2;     #maximum number of electrons in 2nd orbit\n",
+    "e3=2*n3**2;     #maximum number of electrons in 3rd orbit\n",
+    "e4=2*n4**2;     #maximum number of electrons in 4th orbit\n",
+    "e5=2*n5**2;     #maximum number of electrons in 5th orbit\n",
+    "e=e1+e2+e3+e4+e5;      #number of elements\n",
+    "\n",
+    "#Result\n",
+    "print \"number of elements would be\",e"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PMopwvn.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PMopwvn.ipynb
new file mode 100644
index 00000000..ede08994
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_PMopwvn.ipynb
@@ -0,0 +1,588 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 2: Molecular Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 97"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 219.03 cm-1\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda_sample=4358;     #wavelength(angstrom)\n",
+    "lamda_raman=4400;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda_sample)-(10**8/lamda_raman);        #raman shift(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new,2),\"cm-1\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of diatomic molecule is 2.22 *10**-68 J\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.62*10**-34;        #planck's constant\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*math.pi**2);    #energy of diatomic molecule(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of diatomic molecule is\",round(E*10**68,2),\"*10**-68 J\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 0.02 *10**6 m-1\n",
+      "wavelength of antistokes line 4950.5 angstrom\n",
+      "answer for wavelength given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=5000*10**-10;      #wavelength(m)\n",
+    "lamda=5050.5*10**-10;     #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "new0=1/lamda0;       #frequency(m-1)\n",
+    "new=1/lamda;         #frequency(m-1)\n",
+    "delta_new=new0-new;        #raman shift(m-1)\n",
+    "new_as=delta_new+new0;     #frequency of anti-stokes line(m-1)\n",
+    "lamdaas=1*10**10/new_as;          #wavelength of anti-stokes line(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new*10**-6,2),\"*10**6 m-1\"\n",
+    "print \"wavelength of antistokes line\",round(lamdaas,2),\"angstrom\"\n",
+    "print \"answer for wavelength given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy required is 60 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=4.8*10**2;        #force constant(N/m)\n",
+    "x=2*10**-10;        #inter nuclear distance(m)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=k*x**2/(2*e);     #energy required(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy required is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequency of vibration is 2.04 *10**13 sec-1\n",
+      "spacing between energy levels is 8.447 *10**-2 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=187;        #force constant(N/m)\n",
+    "m=1.14*10**-26;     #reduced mass(kg)\n",
+    "h=6.63*10**-34;     #planck's constant\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "new=math.sqrt(k/m)/(2*math.pi);          #frequency of vibration(sec-1)\n",
+    "delta_E=h*new;        #spacing between energy levels(J)\n",
+    "delta_E=delta_E/e;    #spacing between energy levels(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequency of vibration is\",round(new*10**-13,2),\"*10**13 sec-1\"\n",
+    "print \"spacing between energy levels is\",round(delta_E*10**2,3),\"*10**-2 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "internuclear distance is 1.42 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "B=8.5;        #seperation(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "N=6.023*10**23;     #avagadro number\n",
+    "m1=1;\n",
+    "m2=79;         \n",
+    "\n",
+    "#Calculations\n",
+    "I=h/(8*math.pi**2*B*c);    #moment inertia of molecule(gm cm**2)\n",
+    "m=m1*m2/(N*(m1+m2));       #reduced mass(gm)\n",
+    "r=10**8*math.sqrt(I/m);          #internuclear distance(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"internuclear distance is\",round(r,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "vibrational frequency of sample is 1974 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda1=4358.3;     #wavelength(angstrom)\n",
+    "lamda2=4768.5;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda1)-(10**8/lamda2);        #vibrational frequency of sample(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"vibrational frequency of sample is\",int(round(delta_new)),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 101"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequqncy of OD stretching vibration is 2401 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "MO=16;\n",
+    "MD=2;\n",
+    "MH=1;\n",
+    "new=3300;     #frequency(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "mew_OD=MO*MD/(MO+MD);      \n",
+    "mew_OH=MO*MH/(MO+MH);\n",
+    "new1=math.sqrt(mew_OD/mew_OH);\n",
+    "new_OD=new/new1;        #frequqncy of OD stretching vibration(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequqncy of OD stretching vibration is\",int(new_OD),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift of 4400 line is 219.03 cm-1\n",
+      "raman shift of 4419 line is 316.8 cm-1\n",
+      "raman shift of 4447 line is 459.2 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=4358;     #wavelength(angstrom)\n",
+    "lamda1=4400;     #wavelength(angstrom)\n",
+    "lamda2=4419;     #wavelength(angstrom)\n",
+    "lamda3=4447;     #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "new0bar=10**8/lamda0;        #wave number of exciting line(cm-1)\n",
+    "rs1=(10**8/lamda0)-(10**8/lamda1);     #raman shift of 4400 line(cm-1)\n",
+    "rs2=(10**8/lamda0)-(10**8/lamda2);     #raman shift of 4419 line(cm-1)\n",
+    "rs3=(10**8/lamda0)-(10**8/lamda3);     #raman shift of 4447 line(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift of 4400 line is\",round(rs1,2),\"cm-1\"\n",
+    "print \"raman shift of 4419 line is\",round(rs2,1),\"cm-1\"\n",
+    "print \"raman shift of 4447 line is\",round(rs3,1),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelength is 32 *10**-4 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "new_bar=20.68;          #transition(cm-1)\n",
+    "J=14;\n",
+    "\n",
+    "#Calculations\n",
+    "B=new_bar/2;            \n",
+    "new=2*B*(J+1);          #frequency(cm-1)\n",
+    "lamda=1/new;            #corresponding wavelength(cm) \n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelength is\",int(lamda*10**4),\"*10**-4 cm\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 103"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "moment of inertia of molecule is 1.4 *10**-42 gm cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "twoB=4000;        #seperation observed from the series(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "B=twoB/2;\n",
+    "I=h/(8*math.pi**2*B*c);     #moment of inertia of molecule(gm cm**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"moment of inertia of molecule is\",round(I*10**42,1),\"*10**-42 gm cm**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 104"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelengths are 5648 angstrom 5725 angstrom 5775 angstrom 5836 angstrom 5983 angstrom 6558 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda=5461*10**-8;      #wavelength(cm)\n",
+    "new1=608;\n",
+    "new2=846;\n",
+    "new3=995;\n",
+    "new4=1178;\n",
+    "new5=1599; \n",
+    "new6=3064;              #raman shift(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=1/lamda;         #wave number(cm-1)\n",
+    "new11=newbar-new1;\n",
+    "new22=newbar-new2;\n",
+    "new33=newbar-new3;\n",
+    "new44=newbar-new4;\n",
+    "new55=newbar-new5;\n",
+    "new66=newbar-new6;\n",
+    "lamda1=10**8/new11;\n",
+    "lamda2=10**8/new22;\n",
+    "lamda3=10**8/new33;\n",
+    "lamda4=10**8/new44;\n",
+    "lamda5=10**8/new55;\n",
+    "lamda6=10**8/new66;        #corresponding wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelengths are\",int(lamda1),\"angstrom\",int(lamda2),\"angstrom\",int(round(lamda3)),\"angstrom\",int(lamda4),\"angstrom\",int(lamda5),\"angstrom\",int(lamda6),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 105"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "force constant is 115 N/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.63*10**-34;     #planck's constant(J s)\n",
+    "e=1.602*10**-19;    #charge(coulomb)  \n",
+    "mew=1.14*10**-26;   #reduced mass(kg)\n",
+    "deltaE=6.63*10**-2*e;     #energy(J)\n",
+    "\n",
+    "#Calculations\n",
+    "new=deltaE/h;                 #frequency(sec-1)\n",
+    "k=4*math.pi**2*new**2*mew;    #force constant(N/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"force constant is\",int(k),\"N/m\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_TxLgaXP.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_TxLgaXP.ipynb
new file mode 100644
index 00000000..4f050408
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_TxLgaXP.ipynb
@@ -0,0 +1,244 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 10: Nuclear Detectors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "current produced is 1.829 *10**-13 amp\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "n=10;               #number of particles\n",
+    "E=4*10**6;          #energy of alpha particle(eV)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "N=E*n/E1;             #number of ion pairs\n",
+    "q=N*e;                #current produced(amp)\n",
+    "\n",
+    "#Result\n",
+    "print \"current produced is\",round(q*10**13,3),\"*10**-13 amp\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of ion pairs required is 6.25 *10**5\n",
+      "energy of alpha-particles is 21.875 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "v=4;                #voltage sensitivity(div/volt)\n",
+    "d=0.8;              #number of divisions\n",
+    "C=0.5*10**-12;      #capacitance(F)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "V=d/v;              #voltage(V)\n",
+    "q=C*V;              #current(C)\n",
+    "n=q/e;              #number of ion pairs required\n",
+    "E=n*E1/10**6;       #energy of alpha-particles(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"number of ion pairs required is\",n/10**5,\"*10**5\"\n",
+    "print \"energy of alpha-particles is\",E,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 323"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum radial field is 1.89 *10**6 volts/meter\n",
+      "counter will last for 3.7 years\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "V=1000;              #voltage(V)\n",
+    "r=0.0001;            #radius(m)\n",
+    "b=2*10**-2;          #diameter(m)\n",
+    "a=10**-4;\n",
+    "n=10**9;             #number of counts\n",
+    "\n",
+    "#Calculation\n",
+    "Emax=V/(r*math.log(b/a));    #maximum radial field(volts/meter)\n",
+    "N=n/(50*30*60*3000);         #counter will last for(years)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum radial field is\",round(Emax/10**6,2),\"*10**6 volts/meter\"\n",
+    "print \"counter will last for\",round(N,1),\"years\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 324"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of the particle is 1500 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "r=2;               #radius(m)\n",
+    "B=2.5;             #flux density(Wb/m**2)\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "c=3*10**8;         #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculation\n",
+    "E=B*q*r*c*10**-6/q;     #energy of the particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of the particle is\",int(E),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 325"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average current in the circuit is 1.6e-11 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "cr=600;            #counting rate(counts/minute)\n",
+    "e=10**7;           #number of electrons per discharge\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "t=60;              #number of seconds\n",
+    "\n",
+    "#Calculation\n",
+    "n=cr*e;            #number of electrons in 1 minute\n",
+    "q=n*q/t;           #average current in the circuit(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"average current in the circuit is\",q,\"A\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_UQP2Hbl.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_UQP2Hbl.ipynb
new file mode 100644
index 00000000..171aaa2d
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_UQP2Hbl.ipynb
@@ -0,0 +1,396 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 5: Uncertainity Principle"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 0.211 *10**-20 kg m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "hby2pi=1.055*10**-34;      #plancks constant(J s)\n",
+    "deltax=5*10**-14;          #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_px=hby2pi/deltax;    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",delta_px*10**20,\"*10**-20 kg m/sec\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 3.85 *10**-3 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;      #plancks constant(J s)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "v=600;              #speed(m/s)\n",
+    "deltap=(0.005/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**3,2),\"*10**-3 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 3.5 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=3*10**-11;    #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",round(deltap*10**24,1),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in determination of energy is 6.59 *10**-8 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltat=10**-8;       #lifetime of excited atom(sec)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltaE=h/(2*math.pi*deltat*e);    #uncertainity in determination of energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in determination of energy is\",round(deltaE*10**8,2),\"*10**-8 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in measurement of angular momentum is 2.17 *10**-29 Js\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltaphi=math.pi/(180*60*60);      \n",
+    "\n",
+    "#Calculations\n",
+    "deltaL=h/(2*math.pi*deltaphi);    #uncertainity in measurement of angular momentum(Js)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in measurement of angular momentum is\",round(deltaL*10**29,2),\"*10**-29 Js\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 5.27 *10**-34 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "m=25*10**-3;         #mass(kg)\n",
+    "v=400;               #speed(m/s)\n",
+    "deltap=(2/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**34,2),\"*10**-34 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "percentage of uncertainity in momentum is 3.1 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=2*10**-10;    #uncertainity in position(m)\n",
+    "m=9.1*10**-31;       #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "V=1000;              #voltage(V)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #uncertainity in momentum(kg m/s)\n",
+    "p=math.sqrt(2*m*e*V);             #momentum(kg m/s)\n",
+    "pp=deltap*100/p;                  #percentage of uncertainity in momentum\n",
+    "\n",
+    "#Result\n",
+    "print \"percentage of uncertainity in momentum is\",round(pp,1),\"%\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in velocity of electron is 5.79 *10**4 ms-1\n",
+      "uncertainity in velocity of proton is 31.545 ms-1\n",
+      "answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=20*10**-10;   #uncertainity in position(m)\n",
+    "me=9.1*10**-31;      #mass of electron(kg)\n",
+    "mp=1.67*10**-27;     #mass of proton(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "deltave=h/(2*math.pi*deltax*me);      #uncertainity in velocity of electron(ms-1)\n",
+    "deltavp=h/(2*math.pi*deltax*mp);      #uncertainity in velocity of proton(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in velocity of electron is\",round(deltave*10**-4,2),\"*10**4 ms-1\"\n",
+    "print \"uncertainity in velocity of proton is\",round(deltavp,3),\"ms-1\"\n",
+    "print \"answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "minimum uncertainity in momentum is 1.3 *10**-20 kg m/s\n",
+      "minimum kinetic energy of proton is 0.32 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=8*10**-15;    #uncertainity in position(m)\n",
+    "mp=1.67*10**-27;     #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #minimum uncertainity in momentum(kg m/s)\n",
+    "ke=deltap**2/(2*mp*e);            #minimum kinetic energy of proton(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"minimum uncertainity in momentum is\",round(deltap*10**20,1),\"*10**-20 kg m/s\"\n",
+    "print \"minimum kinetic energy of proton is\",round(ke/10**6,2),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_X8mfBi8.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_X8mfBi8.ipynb
new file mode 100644
index 00000000..283605cf
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_X8mfBi8.ipynb
@@ -0,0 +1,236 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 15: Superconductivity"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field at 3K is 0.006281 Tesla\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=0.0106;          #critical field at 0K(Tesla)\n",
+    "T=3;                #temperature(K)\n",
+    "Tc=4.7;             #temperature(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);     #critical field at 3K(Tesla)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field at 3K is\",round(Hc,6),\"Tesla\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 442"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "temperature of superconductor is 1.701 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=5*10**5/(4*math.pi);          #critical field at 0K(Tesla)\n",
+    "Tc=2.69;                         #temperature(K)\n",
+    "Hc=3*10**5/(4*math.pi);          #critical field(Tesla)\n",
+    "\n",
+    "#Calculation\n",
+    "T=Tc*math.sqrt(1-(Hc/H0));       #temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"temperature of superconductor is\",round(T,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical field is 4.3365 *10**4 A/m\n",
+      "critical current of the wire is 408 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "H0=6.5*10**4;          #critical field at 0K(Tesla)\n",
+    "Tc=7.28;               #temperature(K)\n",
+    "T=4.2;                 #temperature(K)\n",
+    "r=1.5*10**-3;          #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "Hc=H0*(1-(T/Tc)**2);          #critical field(Tesla)\n",
+    "Ic=2*math.pi*r*Hc;            #critical current of the wire(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical field is\",round(Hc/10**4,4),\"*10**4 A/m\"\n",
+    "print \"critical current of the wire is\",int(Ic),\"A\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 443"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "critical temperature is 4.124 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m1=199.5;             #isotopic mass\n",
+    "m2=205.4;             #change in mass \n",
+    "Tc1=4.185;            #temperature of mercury(K)\n",
+    "\n",
+    "#Calculation\n",
+    "Tc2=Tc1*math.sqrt(m1/m2);     #critical temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"critical temperature is\",round(Tc2,3),\"K\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 444"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "superconducting transition temperature is 8.106 K\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "T1=3;            #temperature(K)\n",
+    "T2=8;            #temperature(K)\n",
+    "lamda1=39.6;     #penetration depth(nm)\n",
+    "lamda2=173;      #penetration depth(nm)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(lamda1/lamda2)**2;\n",
+    "Tc4=(T2**4-(x*T1**4))/(1-x);\n",
+    "Tc=Tc4**(1/4);   #superconducting transition temperature(K)\n",
+    "\n",
+    "#Result\n",
+    "print \"superconducting transition temperature is\",round(Tc,3),\"K\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_YHbAZL8.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_YHbAZL8.ipynb
new file mode 100644
index 00000000..ede08994
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_YHbAZL8.ipynb
@@ -0,0 +1,588 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 2: Molecular Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 97"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 219.03 cm-1\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda_sample=4358;     #wavelength(angstrom)\n",
+    "lamda_raman=4400;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda_sample)-(10**8/lamda_raman);        #raman shift(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new,2),\"cm-1\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of diatomic molecule is 2.22 *10**-68 J\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.62*10**-34;        #planck's constant\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*math.pi**2);    #energy of diatomic molecule(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of diatomic molecule is\",round(E*10**68,2),\"*10**-68 J\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 0.02 *10**6 m-1\n",
+      "wavelength of antistokes line 4950.5 angstrom\n",
+      "answer for wavelength given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=5000*10**-10;      #wavelength(m)\n",
+    "lamda=5050.5*10**-10;     #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "new0=1/lamda0;       #frequency(m-1)\n",
+    "new=1/lamda;         #frequency(m-1)\n",
+    "delta_new=new0-new;        #raman shift(m-1)\n",
+    "new_as=delta_new+new0;     #frequency of anti-stokes line(m-1)\n",
+    "lamdaas=1*10**10/new_as;          #wavelength of anti-stokes line(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new*10**-6,2),\"*10**6 m-1\"\n",
+    "print \"wavelength of antistokes line\",round(lamdaas,2),\"angstrom\"\n",
+    "print \"answer for wavelength given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy required is 60 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=4.8*10**2;        #force constant(N/m)\n",
+    "x=2*10**-10;        #inter nuclear distance(m)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=k*x**2/(2*e);     #energy required(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy required is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequency of vibration is 2.04 *10**13 sec-1\n",
+      "spacing between energy levels is 8.447 *10**-2 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=187;        #force constant(N/m)\n",
+    "m=1.14*10**-26;     #reduced mass(kg)\n",
+    "h=6.63*10**-34;     #planck's constant\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "new=math.sqrt(k/m)/(2*math.pi);          #frequency of vibration(sec-1)\n",
+    "delta_E=h*new;        #spacing between energy levels(J)\n",
+    "delta_E=delta_E/e;    #spacing between energy levels(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequency of vibration is\",round(new*10**-13,2),\"*10**13 sec-1\"\n",
+    "print \"spacing between energy levels is\",round(delta_E*10**2,3),\"*10**-2 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "internuclear distance is 1.42 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "B=8.5;        #seperation(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "N=6.023*10**23;     #avagadro number\n",
+    "m1=1;\n",
+    "m2=79;         \n",
+    "\n",
+    "#Calculations\n",
+    "I=h/(8*math.pi**2*B*c);    #moment inertia of molecule(gm cm**2)\n",
+    "m=m1*m2/(N*(m1+m2));       #reduced mass(gm)\n",
+    "r=10**8*math.sqrt(I/m);          #internuclear distance(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"internuclear distance is\",round(r,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "vibrational frequency of sample is 1974 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda1=4358.3;     #wavelength(angstrom)\n",
+    "lamda2=4768.5;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda1)-(10**8/lamda2);        #vibrational frequency of sample(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"vibrational frequency of sample is\",int(round(delta_new)),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 101"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequqncy of OD stretching vibration is 2401 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "MO=16;\n",
+    "MD=2;\n",
+    "MH=1;\n",
+    "new=3300;     #frequency(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "mew_OD=MO*MD/(MO+MD);      \n",
+    "mew_OH=MO*MH/(MO+MH);\n",
+    "new1=math.sqrt(mew_OD/mew_OH);\n",
+    "new_OD=new/new1;        #frequqncy of OD stretching vibration(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequqncy of OD stretching vibration is\",int(new_OD),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift of 4400 line is 219.03 cm-1\n",
+      "raman shift of 4419 line is 316.8 cm-1\n",
+      "raman shift of 4447 line is 459.2 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=4358;     #wavelength(angstrom)\n",
+    "lamda1=4400;     #wavelength(angstrom)\n",
+    "lamda2=4419;     #wavelength(angstrom)\n",
+    "lamda3=4447;     #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "new0bar=10**8/lamda0;        #wave number of exciting line(cm-1)\n",
+    "rs1=(10**8/lamda0)-(10**8/lamda1);     #raman shift of 4400 line(cm-1)\n",
+    "rs2=(10**8/lamda0)-(10**8/lamda2);     #raman shift of 4419 line(cm-1)\n",
+    "rs3=(10**8/lamda0)-(10**8/lamda3);     #raman shift of 4447 line(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift of 4400 line is\",round(rs1,2),\"cm-1\"\n",
+    "print \"raman shift of 4419 line is\",round(rs2,1),\"cm-1\"\n",
+    "print \"raman shift of 4447 line is\",round(rs3,1),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelength is 32 *10**-4 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "new_bar=20.68;          #transition(cm-1)\n",
+    "J=14;\n",
+    "\n",
+    "#Calculations\n",
+    "B=new_bar/2;            \n",
+    "new=2*B*(J+1);          #frequency(cm-1)\n",
+    "lamda=1/new;            #corresponding wavelength(cm) \n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelength is\",int(lamda*10**4),\"*10**-4 cm\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 103"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "moment of inertia of molecule is 1.4 *10**-42 gm cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "twoB=4000;        #seperation observed from the series(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "B=twoB/2;\n",
+    "I=h/(8*math.pi**2*B*c);     #moment of inertia of molecule(gm cm**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"moment of inertia of molecule is\",round(I*10**42,1),\"*10**-42 gm cm**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 104"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelengths are 5648 angstrom 5725 angstrom 5775 angstrom 5836 angstrom 5983 angstrom 6558 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda=5461*10**-8;      #wavelength(cm)\n",
+    "new1=608;\n",
+    "new2=846;\n",
+    "new3=995;\n",
+    "new4=1178;\n",
+    "new5=1599; \n",
+    "new6=3064;              #raman shift(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=1/lamda;         #wave number(cm-1)\n",
+    "new11=newbar-new1;\n",
+    "new22=newbar-new2;\n",
+    "new33=newbar-new3;\n",
+    "new44=newbar-new4;\n",
+    "new55=newbar-new5;\n",
+    "new66=newbar-new6;\n",
+    "lamda1=10**8/new11;\n",
+    "lamda2=10**8/new22;\n",
+    "lamda3=10**8/new33;\n",
+    "lamda4=10**8/new44;\n",
+    "lamda5=10**8/new55;\n",
+    "lamda6=10**8/new66;        #corresponding wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelengths are\",int(lamda1),\"angstrom\",int(lamda2),\"angstrom\",int(round(lamda3)),\"angstrom\",int(lamda4),\"angstrom\",int(lamda5),\"angstrom\",int(lamda6),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 105"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "force constant is 115 N/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.63*10**-34;     #planck's constant(J s)\n",
+    "e=1.602*10**-19;    #charge(coulomb)  \n",
+    "mew=1.14*10**-26;   #reduced mass(kg)\n",
+    "deltaE=6.63*10**-2*e;     #energy(J)\n",
+    "\n",
+    "#Calculations\n",
+    "new=deltaE/h;                 #frequency(sec-1)\n",
+    "k=4*math.pi**2*new**2*mew;    #force constant(N/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"force constant is\",int(k),\"N/m\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_arYa4fL.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_arYa4fL.ipynb
new file mode 100644
index 00000000..ecefb615
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_arYa4fL.ipynb
@@ -0,0 +1,210 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 8: Alpha and Beta Decays"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 282"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of beta article is 0.8624 c\n",
+      "mass of beta particle is 1.98 m0\n",
+      "flux density is 0.029106 weber/m**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;     #charge(coulomb)\n",
+    "Ek=0.5*10**6;      #kinetic energy(eV)\n",
+    "m0=9.11*10**-31;   #mass(kg)\n",
+    "c=3*10**8;         #velocity of light(m/s)\n",
+    "r=0.1;             #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(Ek*e/(m0*c**2))+1;\n",
+    "y=1-(1/x)**2;\n",
+    "v=c*math.sqrt(y);     #velocity of beta article(m/s)\n",
+    "m=m0/math.sqrt(1-(v/c)**2);     #mass of beta particle(kg)\n",
+    "B=m*v/(e*r);                    #flux density(weber/m**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of beta article is\",round(v/c,4),\"c\"\n",
+    "print \"mass of beta particle is\",round(m/m0,2),\"m0\"\n",
+    "print \"flux density is\",round(B,6),\"weber/m**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of alpha particle is 4.782 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A=226;       #atomic weight\n",
+    "Ra=226.02540;     #mass of Ra\n",
+    "Rn=222.017571;    #mass of Rn\n",
+    "He=4.002603;      #mass of He\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ra-Rn-He)*m;   \n",
+    "kalpha=(A-4)*Q/A;    #kinetic energy of alpha particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of alpha particle is\",round(kalpha,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum kinetic energy of electrons is 4.548 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ne=22.99465;     #mass of Ne\n",
+    "Na=22.989768;    #mass of Na\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ne-Na)*m;     #maximum kinetic energy of electrons(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum kinetic energy of electrons is\",round(Q,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 284"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value of 1st decay is 0.482 MeV\n",
+      "Q value of 2nd decay is 1.504 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "K=39.963999;     #mass of K\n",
+    "Ca=39.962591;    #mass of Ca\n",
+    "Ar=39.962384;    #mass of Ar\n",
+    "me=0.000549;     #mass of electron  \n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q1=(K-Ar-(2*me))*m;   #Q value of 1st decay(MeV)\n",
+    "Q2=(K-Ar)*m;      #Q value of 2nd decay(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q value of 1st decay is\",round(Q1,3),\"MeV\"\n",
+    "print \"Q value of 2nd decay is\",round(Q2,3),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_bIyaeBj.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_bIyaeBj.ipynb
new file mode 100644
index 00000000..1d50ed48
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_bIyaeBj.ipynb
@@ -0,0 +1,384 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 11: Crystal Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 4 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "c=1/4;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 3 2 0 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "x=float(\"inf\");\n",
+    "c=1/x;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "lcm=lcm(1/a,1/b);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 358"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 3 2 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=1/2;\n",
+    "c=1/3;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 359"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding intercept on Y-axis and Z-axis are 0.8 angstrom and 0.65 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1.1;\n",
+    "b=1.2;\n",
+    "c=1.3;     #intercepts along the three axes(angstrom)\n",
+    "h=2;\n",
+    "k=3;\n",
+    "l=4;       #miller indices of plane\n",
+    "\n",
+    "#Calculations\n",
+    "l1=a*h/h;\n",
+    "l2=b*h/k;    #corresponding intercept on Y-axis(angstrom)\n",
+    "l3=c*h/l;    #corresponding intercept on Z-axis(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding intercept on Y-axis and Z-axis are\",l2,\"angstrom and\",l3,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 -2 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=-1/3;\n",
+    "c=1/2;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 3.61 angstrom\n",
+      "distance between two nearest copper atoms is 2.55 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=4;        #number of molecules per unit cell\n",
+    "M=63.5;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=8.96*10**3;    #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "a=round(a*10**10,2);        #lattice constant(angstrom) \n",
+    "d=a/math.sqrt(2);           #distance between two nearest copper atoms(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",a,\"angstrom\"\n",
+    "print \"distance between two nearest copper atoms is\",round(d,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 361"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 2.8687 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=2;        #number of molecules per unit cell\n",
+    "M=55.85;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=7860;          #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",round(a*10**10,4),\"angstrom\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_d87uZsb.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_d87uZsb.ipynb
new file mode 100644
index 00000000..171aaa2d
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_d87uZsb.ipynb
@@ -0,0 +1,396 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 5: Uncertainity Principle"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 0.211 *10**-20 kg m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "hby2pi=1.055*10**-34;      #plancks constant(J s)\n",
+    "deltax=5*10**-14;          #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_px=hby2pi/deltax;    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",delta_px*10**20,\"*10**-20 kg m/sec\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 3.85 *10**-3 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;      #plancks constant(J s)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "v=600;              #speed(m/s)\n",
+    "deltap=(0.005/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**3,2),\"*10**-3 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 3.5 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=3*10**-11;    #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",round(deltap*10**24,1),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in determination of energy is 6.59 *10**-8 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltat=10**-8;       #lifetime of excited atom(sec)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltaE=h/(2*math.pi*deltat*e);    #uncertainity in determination of energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in determination of energy is\",round(deltaE*10**8,2),\"*10**-8 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in measurement of angular momentum is 2.17 *10**-29 Js\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltaphi=math.pi/(180*60*60);      \n",
+    "\n",
+    "#Calculations\n",
+    "deltaL=h/(2*math.pi*deltaphi);    #uncertainity in measurement of angular momentum(Js)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in measurement of angular momentum is\",round(deltaL*10**29,2),\"*10**-29 Js\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 5.27 *10**-34 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "m=25*10**-3;         #mass(kg)\n",
+    "v=400;               #speed(m/s)\n",
+    "deltap=(2/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**34,2),\"*10**-34 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "percentage of uncertainity in momentum is 3.1 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=2*10**-10;    #uncertainity in position(m)\n",
+    "m=9.1*10**-31;       #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "V=1000;              #voltage(V)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #uncertainity in momentum(kg m/s)\n",
+    "p=math.sqrt(2*m*e*V);             #momentum(kg m/s)\n",
+    "pp=deltap*100/p;                  #percentage of uncertainity in momentum\n",
+    "\n",
+    "#Result\n",
+    "print \"percentage of uncertainity in momentum is\",round(pp,1),\"%\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in velocity of electron is 5.79 *10**4 ms-1\n",
+      "uncertainity in velocity of proton is 31.545 ms-1\n",
+      "answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=20*10**-10;   #uncertainity in position(m)\n",
+    "me=9.1*10**-31;      #mass of electron(kg)\n",
+    "mp=1.67*10**-27;     #mass of proton(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "deltave=h/(2*math.pi*deltax*me);      #uncertainity in velocity of electron(ms-1)\n",
+    "deltavp=h/(2*math.pi*deltax*mp);      #uncertainity in velocity of proton(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in velocity of electron is\",round(deltave*10**-4,2),\"*10**4 ms-1\"\n",
+    "print \"uncertainity in velocity of proton is\",round(deltavp,3),\"ms-1\"\n",
+    "print \"answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "minimum uncertainity in momentum is 1.3 *10**-20 kg m/s\n",
+      "minimum kinetic energy of proton is 0.32 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=8*10**-15;    #uncertainity in position(m)\n",
+    "mp=1.67*10**-27;     #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #minimum uncertainity in momentum(kg m/s)\n",
+    "ke=deltap**2/(2*mp*e);            #minimum kinetic energy of proton(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"minimum uncertainity in momentum is\",round(deltap*10**20,1),\"*10**-20 kg m/s\"\n",
+    "print \"minimum kinetic energy of proton is\",round(ke/10**6,2),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dJzyQXE.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dJzyQXE.ipynb
new file mode 100644
index 00000000..a4871749
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dJzyQXE.ipynb
@@ -0,0 +1,681 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 4: Matter Waves"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=3967;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h/(m*v);             #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",int(lamda*10**10),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of electron is 6 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=9.11*10**-31;            #mass of electron(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "lamda=5*10**-10;           #de-Broglie wavelength(m)\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*m*lamda**2*e);     #kinetic energy of electron(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of electron is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 3.97 *10**-6 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;                  #velocity of light(m/sec)\n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;             #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "v=c/30;             #velocity of proton(m/sec)\n",
+    "lamda=h/(m*v);     #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",round(lamda*10**14,2),\"*10**-6 angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of electron is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "V=150;          #potential difference(V)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=12.26/math.sqrt(V);     #de-Broglie wavelength of electron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of electron is\",int(lamda),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength is 1.23 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "V=100;                 #voltage(eV)  \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*e*V);    #de-Broglie wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of neutron is 0.99 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=4000;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/(m*v);             #de-Broglie wavelength of neutron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of neutron is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of kinetic energies of electron and proton is 1833\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mp=1.67*10**-27;            #mass of proton(kg)\n",
+    "me=9.11*10**-31;            #mass of electron(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "r=mp/me;                    #ratio of kinetic energies of electron and proton\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of kinetic energies of electron and proton is\",int(r)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of wavelengths is 32\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "E=1000;                #energy(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "r=math.sqrt(2*m/(e*E))*c;    #ratio of wavelengths\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of wavelengths is\",int(round(r))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of electron is 0.289 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "h=6.6*10**-34;         #planks constant(Js)\n",
+    "lamda=1.54*10**-10;    #wavelength of X-ray(m)\n",
+    "wf=1*10**-15;          #work function(J)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;           #energy of X-ray(J)\n",
+    "Ee=E-wf;               #energy of electron emitted(J)\n",
+    "lamda=h/math.sqrt(2*m*Ee);     #wavelength of electron(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of electron is\",round(lamda*10**10,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 161"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de broglie wavelength of proton is 1.537 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;         #mass of proton(kg)\n",
+    "h=6.6*10**-34;          #planks constant(Js)\n",
+    "T=400;                  #temperature(K)\n",
+    "k=1.38*10**-23;         #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*k*T);     #de broglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de broglie wavelength of proton is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "rest energy of electron is 8.19e-14 J\n",
+      "energy of proton is 8.19e-11 J\n",
+      "velocity of proton is 312902460.506 m/s\n",
+      "wavelength of electron is 1.27 *10**-5 angstrom\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.673*10**-27;        #mass of proton(kg)\n",
+    "m0=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "h=6.63*10**-34;         #planks constant(Js)\n",
+    "ke=1000;                #kinetic energy\n",
+    "\n",
+    "#Calculations\n",
+    "re=m0*c**2;             #rest energy of electron(J)\n",
+    "Ep=ke*re;               #energy of proton(J)\n",
+    "v=math.sqrt(2*Ep/m);     #velocity of proton(m/s)\n",
+    "lamda=h*10**10/(m*v);   #debroglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"rest energy of electron is\",re,\"J\"\n",
+    "print \"energy of proton is\",Ep,\"J\"\n",
+    "print \"velocity of proton is\",v,\"m/s\"\n",
+    "print \"wavelength of electron is\",round(lamda*10**5,2),\"*10**-5 angstrom\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 4.55 *10**7 m/s\n",
+      "kinetic energy is 5887 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "lamda=0.16*10**-10;    #debroglie wavelength of electron(m)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(lamda*m);         #velocity of electron(m/s)\n",
+    "KE=m*v**2/(2*e);       #kinetic energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-7,2),\"*10**7 m/s\"\n",
+    "print \"kinetic energy is\",int(KE),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 163"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "interplanar spacing of crystal is 1.78 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;       #mass of proton(kg)\n",
+    "h=6.62*10**-34;       #planks constant(Js)\n",
+    "T=300;                 #temperature(K)\n",
+    "k=1.38*10**-23;        #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "d=h*10**10/math.sqrt(2*m*k*T);     #interplanar spacing of crystal(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"interplanar spacing of crystal is\",round(d,2),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential is 605.16 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=0.5;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "V=(12.3/lamda)**2;    #potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential is\",V,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of gama ray photon is 19.89 *10**-16 J\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=1*10**-10;      #wavelength(m)\n",
+    "h=6.63*10**-34;       #planks constant(Js)\n",
+    "c=3*10**8;            #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "p=h/lamda;            #momentum(J-sec/m)\n",
+    "E=p*c;                #energy of gama ray photon(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of gama ray photon is\",E*10**16,\"*10**-16 J\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 16, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 2.2 *10**6 m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "h=6.6*10**-34;       #planks constant(Js)\n",
+    "m=9*10**-31;         #mass of electron(kg)\n",
+    "r=0.53*10**-10;      #radius of orbit(m)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(2*math.pi*r*m);   #velocity of electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-6,1),\"*10**6 m/sec\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dV9ikYe.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dV9ikYe.ipynb
new file mode 100644
index 00000000..e9b7b5a0
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_dV9ikYe.ipynb
@@ -0,0 +1,250 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 12: X-ray Diffraction"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.0842 nm\n",
+      "maximum order of diffraction is 6\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=0.282;       #lattice spacing(nm)\n",
+    "theta=(8+(35/60))*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(nm)\n",
+    "n=2*d/lamda;                     #maximum order of diffraction\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"nm\"\n",
+    "print \"maximum order of diffraction is\",int(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 378"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "glancing angle for 1st order is 17 degrees 24 minutes\n",
+      "glancing angle for 2nd order is 36 degrees 44 minutes\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.209;       #lattice spacing(angstrom)\n",
+    "lamda=1.92;    #wavelength of X-rays(angstrom)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order \n",
+    "\n",
+    "#Calculation\n",
+    "theta1=math.asin(n1*lamda/(2*d))*180/math.pi;    #glancing angle for 1st order(degrees)\n",
+    "theta1d=int(theta1);                             #glancing angle for 1st order(degrees)  \n",
+    "theta1m=(theta1-theta1d)*60;                     #glancing angle for 1st order(minutes)\n",
+    "theta2=math.asin(n2*lamda/(2*d))*180/math.pi;    #glancing angle for 2nd order(degrees)\n",
+    "theta2d=int(theta2);                             #glancing angle for 2nd order(degrees)\n",
+    "theta2m=(theta2-theta2d)*60;                     #glancing angle for 2nd order(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"glancing angle for 1st order is\",theta1d,\"degrees\",int(theta1m),\"minutes\"\n",
+    "print \"glancing angle for 2nd order is\",theta2d,\"degrees\",int(theta2m),\"minutes\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 379"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=3.05;       #lattice spacing(angstrom)\n",
+    "theta=12*math.pi/180;     #glancing angle(radian)\n",
+    "n=1;                  #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of line A is 1.268 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "thetaA=30*math.pi/180;     #glancing angle(radian)\n",
+    "thetaB=60*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                  #order\n",
+    "n2=2;                  #order\n",
+    "lamdaB=0.9;            #wavelength of X-rays(angstrom)\n",
+    "\n",
+    "#Calculation\n",
+    "lamdaA=2*lamdaB*math.sin(thetaA)/math.sin(thetaB);    #wavelength of line A(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of line A is\",round(lamda,3),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 380"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of X-rays is 0.7853 angstrom\n",
+      "glancing angle for 2nd order is 18.2 degrees\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "d=2.51;       #lattice spacing(angstrom)\n",
+    "theta=9*math.pi/180;     #glancing angle(radian)\n",
+    "n1=1;                    #order\n",
+    "n2=2;                    #order\n",
+    "\n",
+    "#Calculation\n",
+    "lamda=2*d*math.sin(theta)/n1;    #wavelength of X-rays(angstrom)\n",
+    "theta=math.asin(n2*lamda/(2*d))*180/math.pi; #glancing angle for 2nd order(degrees)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of X-rays is\",round(lamda,4),\"angstrom\"\n",
+    "print \"glancing angle for 2nd order is\",round(theta,1),\"degrees\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_e7YLoLd.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_e7YLoLd.ipynb
new file mode 100644
index 00000000..fd167244
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_e7YLoLd.ipynb
@@ -0,0 +1,304 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 6: Schrodinger Wave Mechanics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 228"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy levels are 38 eV 150 eV 339 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "a=10**-10;            #width(m)\n",
+    "h=6.62*10**-34;       #planck's constant\n",
+    "n1=1;\n",
+    "n2=2;\n",
+    "n3=3;\n",
+    "\n",
+    "#Calculation\n",
+    "Ex=h**2/(8*e*m*a**2);  #energy(eV)\n",
+    "E1=Ex*n1**2;         #energy at 1st level(eV)\n",
+    "E2=Ex*n2**2;         #energy at 2nd level(eV)\n",
+    "E3=Ex*n3**2;         #energy at 3rd level(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy levels are\",int(round(E1)),\"eV\",int(round(E2)),\"eV\",int(round(E3)),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of finding the particle is 0.133\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "deltax=1*10**-10;        #width\n",
+    "a=15*10**-10;            #width(m)\n",
+    "\n",
+    "#Calculation\n",
+    "W=2*deltax/a;            #probability of finding the particle\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of finding the particle is\",round(W,3)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of transmission of electron is 0.5\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=1;          #energy(eV)\n",
+    "V0=2;         #voltage(eV)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "chi=1.05*10**-34;     \n",
+    "a=2*10**-10;          #potential barrier\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(2*m*(V0-E)*e);\n",
+    "y=16*E*(1-(E/V0))/V0;\n",
+    "T=y*math.exp(-2*a*x/chi);     #probability of transmission of electron\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of transmission of electron is\",round(T,1)\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 230"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 32,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons reflected is 0.38\n",
+      "fraction of electrons transmitted is 0.62\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.080*10**-19;          #energy(eV)\n",
+    "E_V0=0.016*10**-19;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "R=(x-y)/(x+y);       #fraction of electrons reflected\n",
+    "T=1-R;                    #fraction of electrons transmitted\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons reflected is\",round(R,2)\n",
+    "print \"fraction of electrons transmitted is\",round(T,2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 231"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 37,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons transmitted is 0.4998\n",
+      "fraction of electrons reflected is 0.5002\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.34;          #energy(eV)\n",
+    "E_V0=0.01;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "T=4*x*y/(x+y)**2;       #fraction of electrons transmitted \n",
+    "R=1-T;                  #fraction of electrons reflected\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons transmitted is\",round(T,4)\n",
+    "print \"fraction of electrons reflected is\",round(R,4)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 232"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 50,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "transmission coefficient is 3.27 *10**-9\n",
+      "transmission coefficient in 1st case is 7.62 *10**-8\n",
+      "transmission coefficient in 2nd case is 1.51 *10**-15\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "E1=1*e;         #energy(J)\n",
+    "E2=2*e;         #energy(J)\n",
+    "V0=5*e;         #voltage(J)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "chi=1.054*10**-34;     \n",
+    "a1=10*10**-10;         #potential barrier(m)\n",
+    "a2=20*10**-10;         #potential barrier(m)\n",
+    "\n",
+    "#Calculation\n",
+    "beta1=math.sqrt(2*m*(V0-E1)/(chi**2));\n",
+    "y1=16*E1*((V0-E1)/(V0**2));\n",
+    "T1=y1*math.exp(-2*a1*beta1);     #transmission coefficient\n",
+    "beta2=math.sqrt(2*m*(V0-E2)/(chi**2));\n",
+    "y2=16*E2*((V0-E2)/(V0**2));\n",
+    "T2=y2*math.exp(-2*a1*beta2);     #transmission coefficient in 1st case\n",
+    "T3=y2*math.exp(-2*a2*beta2);     #transmission coefficient in 2nd case\n",
+    "\n",
+    "#Result\n",
+    "print \"transmission coefficient is\",round(T1*10**9,2),\"*10**-9\"\n",
+    "print \"transmission coefficient in 1st case is\",round(T2*10**8,2),\"*10**-8\"\n",
+    "print \"transmission coefficient in 2nd case is\",round(T3*10**15,2),\"*10**-15\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_eHnfttn.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_eHnfttn.ipynb
new file mode 100644
index 00000000..3725056f
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_eHnfttn.ipynb
@@ -0,0 +1,243 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 13: Bonding In Crystals"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential energy is -5.76 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "r0=2.5*10**-10;         #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-e*x/r0;              #potential energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential energy is\",U,\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 398"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "equilibrium distance is -2.25 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "U=6.4;                  #potential energy(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "r0=-e*x/U;              #equilibrium distance(m)\n",
+    "\n",
+    "\n",
+    "#Result\n",
+    "print \"equilibrium distance is\",r0*10**10,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "compressibility of the solid is -25.087 *10**14\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.76;             #madelung constant\n",
+    "n=0.5;                  #repulsive exponent\n",
+    "r0=4.1*10**-4;          #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "C=18*r0**4/(x*alpha*e**2*(n-1));     #compressibility of the solid\n",
+    "\n",
+    "#Result\n",
+    "print \"compressibility of the solid is\",round(C*10**-14,3),\"*10**14\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -6.45 eV\n",
+      "energy needed to form neutral atoms is -6.17 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.763;            #madelung constant\n",
+    "n=10.5;                 #repulsive exponent\n",
+    "r0=3.56*10**-10;        #equilibrium distance(m)\n",
+    "IE=3.89;                #ionisation energy(eV)\n",
+    "EA=-3.61;               #electron affinity(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "E=U+EA+IE;                            #energy needed to form neutral atoms\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U,2),\"eV\"\n",
+    "print \"energy needed to form neutral atoms is\",round(E,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 400"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice energy is -3.98 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "x=9*10**9;              #assume x=1/(4*pi*epsilon0)\n",
+    "e=1.6*10**-19;          #charge(coulomb)\n",
+    "alpha=1.748;            #madelung constant\n",
+    "n=9;                 #repulsive exponent\n",
+    "r0=2.81*10**-10;        #equilibrium distance(m)\n",
+    "\n",
+    "#Calculation\n",
+    "U=-x*alpha*e**2*(1-(1/n))/(e*r0);     #lattice energy(eV)  \n",
+    "\n",
+    "#Result\n",
+    "print \"lattice energy is\",round(U/2,2),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_fh4Y4P5.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_fh4Y4P5.ipynb
new file mode 100644
index 00000000..4f050408
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_fh4Y4P5.ipynb
@@ -0,0 +1,244 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 10: Nuclear Detectors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "current produced is 1.829 *10**-13 amp\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "n=10;               #number of particles\n",
+    "E=4*10**6;          #energy of alpha particle(eV)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "N=E*n/E1;             #number of ion pairs\n",
+    "q=N*e;                #current produced(amp)\n",
+    "\n",
+    "#Result\n",
+    "print \"current produced is\",round(q*10**13,3),\"*10**-13 amp\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 322"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "number of ion pairs required is 6.25 *10**5\n",
+      "energy of alpha-particles is 21.875 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "v=4;                #voltage sensitivity(div/volt)\n",
+    "d=0.8;              #number of divisions\n",
+    "C=0.5*10**-12;      #capacitance(F)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "E1=35;              #energy of 1 ion pair(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "V=d/v;              #voltage(V)\n",
+    "q=C*V;              #current(C)\n",
+    "n=q/e;              #number of ion pairs required\n",
+    "E=n*E1/10**6;       #energy of alpha-particles(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"number of ion pairs required is\",n/10**5,\"*10**5\"\n",
+    "print \"energy of alpha-particles is\",E,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 323"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum radial field is 1.89 *10**6 volts/meter\n",
+      "counter will last for 3.7 years\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "V=1000;              #voltage(V)\n",
+    "r=0.0001;            #radius(m)\n",
+    "b=2*10**-2;          #diameter(m)\n",
+    "a=10**-4;\n",
+    "n=10**9;             #number of counts\n",
+    "\n",
+    "#Calculation\n",
+    "Emax=V/(r*math.log(b/a));    #maximum radial field(volts/meter)\n",
+    "N=n/(50*30*60*3000);         #counter will last for(years)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum radial field is\",round(Emax/10**6,2),\"*10**6 volts/meter\"\n",
+    "print \"counter will last for\",round(N,1),\"years\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 324"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of the particle is 1500 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "r=2;               #radius(m)\n",
+    "B=2.5;             #flux density(Wb/m**2)\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "c=3*10**8;         #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculation\n",
+    "E=B*q*r*c*10**-6/q;     #energy of the particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of the particle is\",int(E),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 325"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average current in the circuit is 1.6e-11 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "cr=600;            #counting rate(counts/minute)\n",
+    "e=10**7;           #number of electrons per discharge\n",
+    "q=1.6*10**-19;     #charge(coulomb)\n",
+    "t=60;              #number of seconds\n",
+    "\n",
+    "#Calculation\n",
+    "n=cr*e;            #number of electrons in 1 minute\n",
+    "q=n*q/t;           #average current in the circuit(A)\n",
+    "\n",
+    "#Result\n",
+    "print \"average current in the circuit is\",q,\"A\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_hbRKWYG.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_hbRKWYG.ipynb
new file mode 100644
index 00000000..ede08994
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_hbRKWYG.ipynb
@@ -0,0 +1,588 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 2: Molecular Spectra"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 97"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 219.03 cm-1\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda_sample=4358;     #wavelength(angstrom)\n",
+    "lamda_raman=4400;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda_sample)-(10**8/lamda_raman);        #raman shift(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new,2),\"cm-1\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of diatomic molecule is 2.22 *10**-68 J\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.62*10**-34;        #planck's constant\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*math.pi**2);    #energy of diatomic molecule(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of diatomic molecule is\",round(E*10**68,2),\"*10**-68 J\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 98"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift is 0.02 *10**6 m-1\n",
+      "wavelength of antistokes line 4950.5 angstrom\n",
+      "answer for wavelength given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=5000*10**-10;      #wavelength(m)\n",
+    "lamda=5050.5*10**-10;     #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "new0=1/lamda0;       #frequency(m-1)\n",
+    "new=1/lamda;         #frequency(m-1)\n",
+    "delta_new=new0-new;        #raman shift(m-1)\n",
+    "new_as=delta_new+new0;     #frequency of anti-stokes line(m-1)\n",
+    "lamdaas=1*10**10/new_as;          #wavelength of anti-stokes line(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift is\",round(delta_new*10**-6,2),\"*10**6 m-1\"\n",
+    "print \"wavelength of antistokes line\",round(lamdaas,2),\"angstrom\"\n",
+    "print \"answer for wavelength given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy required is 60 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=4.8*10**2;        #force constant(N/m)\n",
+    "x=2*10**-10;        #inter nuclear distance(m)\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=k*x**2/(2*e);     #energy required(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy required is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 99"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequency of vibration is 2.04 *10**13 sec-1\n",
+      "spacing between energy levels is 8.447 *10**-2 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "k=187;        #force constant(N/m)\n",
+    "m=1.14*10**-26;     #reduced mass(kg)\n",
+    "h=6.63*10**-34;     #planck's constant\n",
+    "e=1.6*10**-19;      #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "new=math.sqrt(k/m)/(2*math.pi);          #frequency of vibration(sec-1)\n",
+    "delta_E=h*new;        #spacing between energy levels(J)\n",
+    "delta_E=delta_E/e;    #spacing between energy levels(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequency of vibration is\",round(new*10**-13,2),\"*10**13 sec-1\"\n",
+    "print \"spacing between energy levels is\",round(delta_E*10**2,3),\"*10**-2 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "internuclear distance is 1.42 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "B=8.5;        #seperation(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "N=6.023*10**23;     #avagadro number\n",
+    "m1=1;\n",
+    "m2=79;         \n",
+    "\n",
+    "#Calculations\n",
+    "I=h/(8*math.pi**2*B*c);    #moment inertia of molecule(gm cm**2)\n",
+    "m=m1*m2/(N*(m1+m2));       #reduced mass(gm)\n",
+    "r=10**8*math.sqrt(I/m);          #internuclear distance(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"internuclear distance is\",round(r,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 100"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "vibrational frequency of sample is 1974 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda1=4358.3;     #wavelength(angstrom)\n",
+    "lamda2=4768.5;      #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_new=(10**8/lamda1)-(10**8/lamda2);        #vibrational frequency of sample(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"vibrational frequency of sample is\",int(round(delta_new)),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 101"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "frequqncy of OD stretching vibration is 2401 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "MO=16;\n",
+    "MD=2;\n",
+    "MH=1;\n",
+    "new=3300;     #frequency(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "mew_OD=MO*MD/(MO+MD);      \n",
+    "mew_OH=MO*MH/(MO+MH);\n",
+    "new1=math.sqrt(mew_OD/mew_OH);\n",
+    "new_OD=new/new1;        #frequqncy of OD stretching vibration(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"frequqncy of OD stretching vibration is\",int(new_OD),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "raman shift of 4400 line is 219.03 cm-1\n",
+      "raman shift of 4419 line is 316.8 cm-1\n",
+      "raman shift of 4447 line is 459.2 cm-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda0=4358;     #wavelength(angstrom)\n",
+    "lamda1=4400;     #wavelength(angstrom)\n",
+    "lamda2=4419;     #wavelength(angstrom)\n",
+    "lamda3=4447;     #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "new0bar=10**8/lamda0;        #wave number of exciting line(cm-1)\n",
+    "rs1=(10**8/lamda0)-(10**8/lamda1);     #raman shift of 4400 line(cm-1)\n",
+    "rs2=(10**8/lamda0)-(10**8/lamda2);     #raman shift of 4419 line(cm-1)\n",
+    "rs3=(10**8/lamda0)-(10**8/lamda3);     #raman shift of 4447 line(cm-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"raman shift of 4400 line is\",round(rs1,2),\"cm-1\"\n",
+    "print \"raman shift of 4419 line is\",round(rs2,1),\"cm-1\"\n",
+    "print \"raman shift of 4447 line is\",round(rs3,1),\"cm-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 102"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelength is 32 *10**-4 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "new_bar=20.68;          #transition(cm-1)\n",
+    "J=14;\n",
+    "\n",
+    "#Calculations\n",
+    "B=new_bar/2;            \n",
+    "new=2*B*(J+1);          #frequency(cm-1)\n",
+    "lamda=1/new;            #corresponding wavelength(cm) \n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelength is\",int(lamda*10**4),\"*10**-4 cm\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 103"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "moment of inertia of molecule is 1.4 *10**-42 gm cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "twoB=4000;        #seperation observed from the series(cm-1)\n",
+    "h=6.62*10**-27;     #planck's constant\n",
+    "c=3*10**10;         #velocity of light(cm/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "B=twoB/2;\n",
+    "I=h/(8*math.pi**2*B*c);     #moment of inertia of molecule(gm cm**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"moment of inertia of molecule is\",round(I*10**42,1),\"*10**-42 gm cm**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 104"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding wavelengths are 5648 angstrom 5725 angstrom 5775 angstrom 5836 angstrom 5983 angstrom 6558 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "lamda=5461*10**-8;      #wavelength(cm)\n",
+    "new1=608;\n",
+    "new2=846;\n",
+    "new3=995;\n",
+    "new4=1178;\n",
+    "new5=1599; \n",
+    "new6=3064;              #raman shift(cm-1)\n",
+    "\n",
+    "#Calculations\n",
+    "newbar=1/lamda;         #wave number(cm-1)\n",
+    "new11=newbar-new1;\n",
+    "new22=newbar-new2;\n",
+    "new33=newbar-new3;\n",
+    "new44=newbar-new4;\n",
+    "new55=newbar-new5;\n",
+    "new66=newbar-new6;\n",
+    "lamda1=10**8/new11;\n",
+    "lamda2=10**8/new22;\n",
+    "lamda3=10**8/new33;\n",
+    "lamda4=10**8/new44;\n",
+    "lamda5=10**8/new55;\n",
+    "lamda6=10**8/new66;        #corresponding wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding wavelengths are\",int(lamda1),\"angstrom\",int(lamda2),\"angstrom\",int(round(lamda3)),\"angstrom\",int(lamda4),\"angstrom\",int(lamda5),\"angstrom\",int(lamda6),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 105"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "force constant is 115 N/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration   \n",
+    "h=6.63*10**-34;     #planck's constant(J s)\n",
+    "e=1.602*10**-19;    #charge(coulomb)  \n",
+    "mew=1.14*10**-26;   #reduced mass(kg)\n",
+    "deltaE=6.63*10**-2*e;     #energy(J)\n",
+    "\n",
+    "#Calculations\n",
+    "new=deltaE/h;                 #frequency(sec-1)\n",
+    "k=4*math.pi**2*new**2*mew;    #force constant(N/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"force constant is\",int(k),\"N/m\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_icFPVil.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_icFPVil.ipynb
new file mode 100644
index 00000000..72f70169
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_icFPVil.ipynb
@@ -0,0 +1,540 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 3: Inadequacy of Classical Physics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum energy of photoelectron is 3.038 *10**-19 J\n",
+      "maximum velocity of electron is 8.17 *10**5 ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=1700*10**-10;       #wavelength(m)\n",
+    "lamda0=2300*10**-10;      #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "KE=h*c*((1/lamda)-(1/lamda0));       #maximum energy of photoelectron(J)\n",
+    "vmax=math.sqrt(2*KE/me);             #maximum velocity of electron(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum energy of photoelectron is\",round(KE*10**19,3),\"*10**-19 J\"\n",
+    "print \"maximum velocity of electron is\",round(vmax/10**5,2),\"*10**5 ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold wavelength is 5380 angstrom\n",
+      "since wavelength of orange light is more, photoelectric effect doesn't take place\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=2.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=6850;               #wavelength of orange light(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda0=h*c/W;             #threshold wavelength(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold wavelength is\",int(lamda0*10**10),\"angstrom\"\n",
+    "print \"since wavelength of orange light is more, photoelectric effect doesn't take place\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "retarding potential is 1.175 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=1.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "new=6*10**14;             #frequency(Hertz)\n",
+    "\n",
+    "#Calculations\n",
+    "V0=((h*new)-W)/e;         #retarding potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"retarding potential is\",V0,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "work function is 1.28 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=3*10**-7;           #wavelength(m)\n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "v=1*10**6;                #velocity(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "W=(h*c/lamda)-(me*v**2/2);      #work function(J)\n",
+    "W=W/e;                          #work function(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"work function is\",round(W,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "photoelectric current is 1.86 micro ampere\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=4600*10**-10;       #wavelength(m)\n",
+    "qe=0.5;                   #efficiency(%)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;              #energy(J)\n",
+    "n=10**-3/E;               #number of photons/second\n",
+    "i=n*qe*e*10**6/100;       #photoelectric current(micro ampere)\n",
+    "\n",
+    "#Result\n",
+    "print \"photoelectric current is\",round(i,2),\"micro ampere\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 130"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "planck's constant is 6.61 *10**-34 joule second\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=3*10**-19;             #temperature(J)\n",
+    "T2=1*10**-19;             #temperature(J)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda1=3350;              #wavelength(m)\n",
+    "lamda2=5060;              #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "x=10**10*((1/lamda1)-(1/lamda2));\n",
+    "h=(T1-T2)/(c*x);          #planck's constant(joule second)\n",
+    "\n",
+    "#Result\n",
+    "print \"planck's constant is\",round(h*10**34,2),\"*10**-34 joule second\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 131"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 3.0121 angstrom\n",
+      "energy of recoil electron is 2.66 *10**-18 joule\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=60*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(angstrom)\n",
+    "lamda_dash=3.058;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "lamda_dash=round(lamda_dash*10**10,4)*10**-10;     #wavelength of scattered radiation(m)\n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash*10**10,\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**18,2),\"*10**-18 joule\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 132"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 2.003 angstrom\n",
+      "velocity of recoil electron is 0.0188 *10**8 ms-1\n",
+      "answer for velocity given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=30*math.pi/180;    #angle(radian)\n",
+    "lamda=2*10**-10;         #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=1+(E/(m0*c**2));\n",
+    "v=c*math.sqrt(1-((1/x)**2));                       #velocity of recoil electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"velocity of recoil electron is\",round(v/10**8,4),\"*10**8 ms-1\"\n",
+    "print \"answer for velocity given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 133"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 49,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered photon is 3.024 angstrom\n",
+      "energy of recoil electron is 0.5 *10**-17 joules\n",
+      "direction of recoil electron is 44 degrees 46 minutes\n",
+      "answer for angle given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(m)   \n",
+    "\n",
+    "#Calculations\n",
+    "lamda_dash=lamda+(h*(1-math.cos(theta))/(m0*c));   #wavelength of scattered photon(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=h/(lamda*m0*c);\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered photon is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**17,1),\"*10**-17 joules\"\n",
+    "print \"direction of recoil electron is\",int(phi),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for angle given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 134"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 51,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of scattered photon is 0.226 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=180*math.pi/180;   #angle(radian)\n",
+    "E=1.96*10**6*e;          #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=2*h/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;   #wavelength of scattered photon(m)    \n",
+    "Edash=h*c/(e*lamda_dash);       #energy of scattered photon(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of scattered photon is\",round(Edash/10**6,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 135"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 65,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 4.9e-12 m\n",
+      "energy of recoil electron is 3.9592 *10**-14 Joules\n",
+      "direction of recoil electron is 27 degrees 47 minutes\n",
+      "answer for energy and direction of recoil electron and given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.6*10**-34;           #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "E=500*10**3*e;           #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=h*(1-math.cos(theta))/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;           #wavelength of scattered radiation(m) \n",
+    "lamda_dash=round(lamda_dash*10**12,1)*10**-12;   #wavelength of scattered radiation(m) \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));       #energy of recoil electron(J)\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash,\"m\"\n",
+    "print \"energy of recoil electron is\",round(E*10**14,4),\"*10**-14 Joules\"\n",
+    "print \"direction of recoil electron is\",int(round(phi)),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for energy and direction of recoil electron and given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_kEBkdeu.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_kEBkdeu.ipynb
new file mode 100644
index 00000000..449a8ffa
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_kEBkdeu.ipynb
@@ -0,0 +1,320 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 14: Magnetism"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 20 *10**9 A/m\n",
+      "flux density is 1.2818 *10**6 T\n",
+      "answer for flux density given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**12;                  #magnetic field intensity(A/m)\n",
+    "chi=20*10**-3;             #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #magnetisation(A/m)\n",
+    "B=mew0*(M+H);              #flux density(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M/10**9),\"*10**9 A/m\"\n",
+    "print \"flux density is\",round(B/10**6,4),\"*10**6 T\"\n",
+    "print \"answer for flux density given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 17725 A/m\n",
+      "answer for magnetisation given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**2;                  #magnetic field intensity(A/m)\n",
+    "B=0.0224;                  #flux density(T)\n",
+    "\n",
+    "#Calculations\n",
+    "M=(B/mew0)-H;              #magnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M),\"A/m\"\n",
+    "print \"answer for magnetisation given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "change in magnetic moment is 5.27 *10**-29 Am**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "r=5*10**-11;               #radius(m)\n",
+    "B=3;                       #flux density(T)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "mew=B*e**2*r**2/(4*m);     #change in magnetic moment(Am**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"change in magnetic moment is\",round(mew*10**29,2),\"*10**-29 Am**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "susceptibility is 0.8 *10**-4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=200;          #temperature(K)\n",
+    "T2=300;          #temperature(K)\n",
+    "chi1=1.2*10**-4; #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "chi2=T1*chi1/T2;    #susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"susceptibility is\",chi2*10**4,\"*10**-4\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "paramagnetisation is 3.6 *10**2 A/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "H=10**5;                  #magnetic field intensity(A/m)\n",
+    "chi=3.6*10**-3;            #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #paramagnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"paramagnetisation is\",M/10**2,\"*10**2 A/m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment is 5.655 *10**-24 Am**2\n",
+      "saturation magnetic induction is 6.5 *10**-4 T\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "mewB=9.27*10**-24;         \n",
+    "rho=8906;                  #density(kg/m**3)\n",
+    "N=6.023*10**23;            #avagadro number\n",
+    "W=58.7;                    #atomic weight\n",
+    "\n",
+    "#Calculations\n",
+    "mewM=0.61*mewB;            #magnetic moment(Am**2)\n",
+    "B=rho*N*mew0*mewM/W;       #saturation magnetic induction(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment is\",round(mewM*10**24,3),\"*10**-24 Am**2\"\n",
+    "print \"saturation magnetic induction is\",round(B*10**4,1),\"*10**-4 T\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 423"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "diamagnetic susceptibility is -8.249 *10**-8\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "R=0.5*10**-10;             #radius(m)\n",
+    "N=28*10**26;               #number of atoms\n",
+    "Z=2;                       #atomic number\n",
+    "\n",
+    "#Calculations\n",
+    "chi_dia=-mew0*Z*e**2*N*R**2/(6*m);    #diamagnetic susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"diamagnetic susceptibility is\",round(chi_dia*10**8,3),\"*10**-8\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_lSt1FDp.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_lSt1FDp.ipynb
new file mode 100644
index 00000000..31b7323a
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_lSt1FDp.ipynb
@@ -0,0 +1,277 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 7: Nuclear Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "radius of He is 2.2375 fermi\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A1=165;               #mass number\n",
+    "A2=4;                 #mass number\n",
+    "R1=7.731;             #radius(fermi)\n",
+    "\n",
+    "#Calculation\n",
+    "R2=R1*(A2/A1)**(1/3);     #radius of He(fermi)\n",
+    "\n",
+    "#Result\n",
+    "print \"radius of He is\",round(R2,4),\"fermi\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average binding energy per nucleon is 7.07 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "alpha=4.00150;        #mass of alpha particle(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=2*(p+n)-alpha;\n",
+    "BE=deltam*m;          #binding energy(MeV)\n",
+    "ABE=BE/4;             #average binding energy per nucleon(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"average binding energy per nucleon is\",round(ABE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 7.25 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Li36=6.015125;        #mass of Li(amu)\n",
+    "Li37=7.016004;        #mass of Li(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Li36+n-Li37;   \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy released is 23.6 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "BEHe=4*7.0;        #binding energy for He\n",
+    "BEH=2*1.1;         #binding energy for H\n",
+    "\n",
+    "#Calculation\n",
+    "deltaE=BEHe-(2*BEH);     #energy released(MeV)   \n",
+    "\n",
+    "#Result\n",
+    "print \"energy released is\",deltaE,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "mass is 19.987 amu\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "BE=160.647;           #binding energy(MeV)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "Mx=10*(p+n)-(BE/m);   #mass(amu)\n",
+    "\n",
+    "#Result\n",
+    "print \"mass is\",round(Mx,3),\"amu\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 261"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 11.471 MeV\n",
+      "answer given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Ca41=40.962278;       #mass of Ca(amu)\n",
+    "Ca42=41.958622;       #mass of Ca(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Ca41+n-Ca42;     \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,3),\"MeV\"\n",
+    "print \"answer given in the book varies due to rounding off errors\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_oqU54mr.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_oqU54mr.ipynb
new file mode 100644
index 00000000..1d50ed48
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_oqU54mr.ipynb
@@ -0,0 +1,384 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 11: Crystal Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 4 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "c=1/4;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 357"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 3 2 0 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/2;\n",
+    "b=1/3;\n",
+    "x=float(\"inf\");\n",
+    "c=1/x;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "lcm=lcm(1/a,1/b);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 358"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 3 2 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=1/2;\n",
+    "c=1/3;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 359"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "corresponding intercept on Y-axis and Z-axis are 0.8 angstrom and 0.65 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1.1;\n",
+    "b=1.2;\n",
+    "c=1.3;     #intercepts along the three axes(angstrom)\n",
+    "h=2;\n",
+    "k=3;\n",
+    "l=4;       #miller indices of plane\n",
+    "\n",
+    "#Calculations\n",
+    "l1=a*h/h;\n",
+    "l2=b*h/k;    #corresponding intercept on Y-axis(angstrom)\n",
+    "l3=c*h/l;    #corresponding intercept on Z-axis(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"corresponding intercept on Y-axis and Z-axis are\",l2,\"angstrom and\",l3,\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "miller indices of plane are ( 6 -2 3 )\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "a=1/1;\n",
+    "b=-1/3;\n",
+    "c=1/2;     #intercepts along the three axes\n",
+    "\n",
+    "#Calculations\n",
+    "def lcm(x, y):\n",
+    "    if x > y:\n",
+    "        greater = x\n",
+    "    else:\n",
+    "        greater = y\n",
+    "    while(True):\n",
+    "        if((greater % x == 0) and (greater % y == 0)):\n",
+    "            lcm = greater\n",
+    "            break\n",
+    "        greater += 1\n",
+    "        \n",
+    "    return lcm\n",
+    "\n",
+    "z=lcm(1/a,1/b);\n",
+    "lcm=lcm(z,1/c);\n",
+    "h=a*lcm;\n",
+    "k=b*lcm;\n",
+    "l=c*lcm;      #miller indices of plane\n",
+    "\n",
+    "#Result\n",
+    "print \"miller indices of plane are (\",int(h),int(k),int(l),\")\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 3.61 angstrom\n",
+      "distance between two nearest copper atoms is 2.55 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=4;        #number of molecules per unit cell\n",
+    "M=63.5;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=8.96*10**3;    #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "a=round(a*10**10,2);        #lattice constant(angstrom) \n",
+    "d=a/math.sqrt(2);           #distance between two nearest copper atoms(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",a,\"angstrom\"\n",
+    "print \"distance between two nearest copper atoms is\",round(d,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 361"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "lattice constant is 2.8687 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration    \n",
+    "n=2;        #number of molecules per unit cell\n",
+    "M=55.85;     #molecular weight\n",
+    "N=6.02*10**26;     #avagadro number(kg mol-1)\n",
+    "rho=7860;          #density(kg/m**3)\n",
+    "\n",
+    "#Calculations\n",
+    "a=(n*M/(rho*N))**(1/3);     #lattice constant(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"lattice constant is\",round(a*10**10,4),\"angstrom\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_rcid83s.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_rcid83s.ipynb
new file mode 100644
index 00000000..ecefb615
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_rcid83s.ipynb
@@ -0,0 +1,210 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 8: Alpha and Beta Decays"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 282"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of beta article is 0.8624 c\n",
+      "mass of beta particle is 1.98 m0\n",
+      "flux density is 0.029106 weber/m**2\n",
+      "answer in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;     #charge(coulomb)\n",
+    "Ek=0.5*10**6;      #kinetic energy(eV)\n",
+    "m0=9.11*10**-31;   #mass(kg)\n",
+    "c=3*10**8;         #velocity of light(m/s)\n",
+    "r=0.1;             #radius(m)\n",
+    "\n",
+    "#Calculation\n",
+    "x=(Ek*e/(m0*c**2))+1;\n",
+    "y=1-(1/x)**2;\n",
+    "v=c*math.sqrt(y);     #velocity of beta article(m/s)\n",
+    "m=m0/math.sqrt(1-(v/c)**2);     #mass of beta particle(kg)\n",
+    "B=m*v/(e*r);                    #flux density(weber/m**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of beta article is\",round(v/c,4),\"c\"\n",
+    "print \"mass of beta particle is\",round(m/m0,2),\"m0\"\n",
+    "print \"flux density is\",round(B,6),\"weber/m**2\"\n",
+    "print \"answer in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of alpha particle is 4.782 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A=226;       #atomic weight\n",
+    "Ra=226.02540;     #mass of Ra\n",
+    "Rn=222.017571;    #mass of Rn\n",
+    "He=4.002603;      #mass of He\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ra-Rn-He)*m;   \n",
+    "kalpha=(A-4)*Q/A;    #kinetic energy of alpha particle(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of alpha particle is\",round(kalpha,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 283"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum kinetic energy of electrons is 4.548 MeV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ne=22.99465;     #mass of Ne\n",
+    "Na=22.989768;    #mass of Na\n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q=(Ne-Na)*m;     #maximum kinetic energy of electrons(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum kinetic energy of electrons is\",round(Q,3),\"MeV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 284"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Q value of 1st decay is 0.482 MeV\n",
+      "Q value of 2nd decay is 1.504 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "K=39.963999;     #mass of K\n",
+    "Ca=39.962591;    #mass of Ca\n",
+    "Ar=39.962384;    #mass of Ar\n",
+    "me=0.000549;     #mass of electron  \n",
+    "m=931.5; \n",
+    "\n",
+    "#Calculation\n",
+    "Q1=(K-Ar-(2*me))*m;   #Q value of 1st decay(MeV)\n",
+    "Q2=(K-Ar)*m;      #Q value of 2nd decay(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"Q value of 1st decay is\",round(Q1,3),\"MeV\"\n",
+    "print \"Q value of 2nd decay is\",round(Q2,3),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_s0Hwrru.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_s0Hwrru.ipynb
new file mode 100644
index 00000000..a4871749
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_s0Hwrru.ipynb
@@ -0,0 +1,681 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 4: Matter Waves"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=3967;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h/(m*v);             #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",int(lamda*10**10),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "kinetic energy of electron is 6 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=9.11*10**-31;            #mass of electron(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "lamda=5*10**-10;           #de-Broglie wavelength(m)\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h**2/(2*m*lamda**2*e);     #kinetic energy of electron(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"kinetic energy of electron is\",int(E),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 158"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of proton is 3.97 *10**-6 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;                  #velocity of light(m/sec)\n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;             #planks constant(Js)\n",
+    "\n",
+    "#Calculations\n",
+    "v=c/30;             #velocity of proton(m/sec)\n",
+    "lamda=h/(m*v);     #de-Broglie wavelength of proton(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of proton is\",round(lamda*10**14,2),\"*10**-6 angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of electron is 1 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "V=150;          #potential difference(V)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=12.26/math.sqrt(V);     #de-Broglie wavelength of electron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of electron is\",int(lamda),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength is 1.23 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "V=100;                 #voltage(eV)  \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*e*V);    #de-Broglie wavelength(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 159"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de-Broglie wavelength of neutron is 0.99 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "m=1.67*10**-27;            #mass of proton(kg)\n",
+    "h=6.625*10**-34;           #planks constant(Js)\n",
+    "v=4000;                    #velocity of proton(m/s)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/(m*v);             #de-Broglie wavelength of neutron(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de-Broglie wavelength of neutron is\",round(lamda,2),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of kinetic energies of electron and proton is 1833\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mp=1.67*10**-27;            #mass of proton(kg)\n",
+    "me=9.11*10**-31;            #mass of electron(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "r=mp/me;                    #ratio of kinetic energies of electron and proton\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of kinetic energies of electron and proton is\",int(r)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ratio of wavelengths is 32\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of proton(kg)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "E=1000;                #energy(eV)\n",
+    "\n",
+    "#Calculations\n",
+    "r=math.sqrt(2*m/(e*E))*c;    #ratio of wavelengths\n",
+    "\n",
+    "#Result\n",
+    "print \"ratio of wavelengths is\",int(round(r))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 160"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of electron is 0.289 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;             #velocity of light(m/sec)\n",
+    "h=6.6*10**-34;         #planks constant(Js)\n",
+    "lamda=1.54*10**-10;    #wavelength of X-ray(m)\n",
+    "wf=1*10**-15;          #work function(J)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;           #energy of X-ray(J)\n",
+    "Ee=E-wf;               #energy of electron emitted(J)\n",
+    "lamda=h/math.sqrt(2*m*Ee);     #wavelength of electron(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of electron is\",round(lamda*10**10,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 161"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "de broglie wavelength of proton is 1.537 angstrom\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;         #mass of proton(kg)\n",
+    "h=6.6*10**-34;          #planks constant(Js)\n",
+    "T=400;                  #temperature(K)\n",
+    "k=1.38*10**-23;         #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*10**10/math.sqrt(2*m*k*T);     #de broglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"de broglie wavelength of proton is\",round(lamda,3),\"angstrom\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "rest energy of electron is 8.19e-14 J\n",
+      "energy of proton is 8.19e-11 J\n",
+      "velocity of proton is 312902460.506 m/s\n",
+      "wavelength of electron is 1.27 *10**-5 angstrom\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.673*10**-27;        #mass of proton(kg)\n",
+    "m0=9.1*10**-31;         #mass of electron(kg)\n",
+    "c=3*10**8;              #velocity of light(m/sec)\n",
+    "h=6.63*10**-34;         #planks constant(Js)\n",
+    "ke=1000;                #kinetic energy\n",
+    "\n",
+    "#Calculations\n",
+    "re=m0*c**2;             #rest energy of electron(J)\n",
+    "Ep=ke*re;               #energy of proton(J)\n",
+    "v=math.sqrt(2*Ep/m);     #velocity of proton(m/s)\n",
+    "lamda=h*10**10/(m*v);   #debroglie wavelength of proton(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"rest energy of electron is\",re,\"J\"\n",
+    "print \"energy of proton is\",Ep,\"J\"\n",
+    "print \"velocity of proton is\",v,\"m/s\"\n",
+    "print \"wavelength of electron is\",round(lamda*10**5,2),\"*10**-5 angstrom\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 162"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 4.55 *10**7 m/s\n",
+      "kinetic energy is 5887 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=9.1*10**-31;         #mass of electron(kg)\n",
+    "h=6.625*10**-34;       #planks constant(Js)\n",
+    "lamda=0.16*10**-10;    #debroglie wavelength of electron(m)\n",
+    "e=1.6*10**-19;         #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(lamda*m);         #velocity of electron(m/s)\n",
+    "KE=m*v**2/(2*e);       #kinetic energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-7,2),\"*10**7 m/s\"\n",
+    "print \"kinetic energy is\",int(KE),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 163"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "interplanar spacing of crystal is 1.78 angstrom\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "m=1.67*10**-27;       #mass of proton(kg)\n",
+    "h=6.62*10**-34;       #planks constant(Js)\n",
+    "T=300;                 #temperature(K)\n",
+    "k=1.38*10**-23;        #boltzmann constant\n",
+    "\n",
+    "#Calculations\n",
+    "d=h*10**10/math.sqrt(2*m*k*T);     #interplanar spacing of crystal(angstrom)\n",
+    "\n",
+    "#Result\n",
+    "print \"interplanar spacing of crystal is\",round(d,2),\"angstrom\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "potential is 605.16 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=0.5;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "V=(12.3/lamda)**2;    #potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"potential is\",V,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 15, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of gama ray photon is 19.89 *10**-16 J\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "lamda=1*10**-10;      #wavelength(m)\n",
+    "h=6.63*10**-34;       #planks constant(Js)\n",
+    "c=3*10**8;            #velocity of light(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "p=h/lamda;            #momentum(J-sec/m)\n",
+    "E=p*c;                #energy of gama ray photon(J)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of gama ray photon is\",E*10**16,\"*10**-16 J\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 16, Page number 164"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity of electron is 2.2 *10**6 m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration \n",
+    "h=6.6*10**-34;       #planks constant(Js)\n",
+    "m=9*10**-31;         #mass of electron(kg)\n",
+    "r=0.53*10**-10;      #radius of orbit(m)\n",
+    "\n",
+    "#Calculations\n",
+    "v=h/(2*math.pi*r*m);   #velocity of electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"velocity of electron is\",round(v*10**-6,1),\"*10**6 m/sec\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_ufxQ3hX.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_ufxQ3hX.ipynb
new file mode 100644
index 00000000..449a8ffa
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_ufxQ3hX.ipynb
@@ -0,0 +1,320 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 14: Magnetism"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 20 *10**9 A/m\n",
+      "flux density is 1.2818 *10**6 T\n",
+      "answer for flux density given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**12;                  #magnetic field intensity(A/m)\n",
+    "chi=20*10**-3;             #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #magnetisation(A/m)\n",
+    "B=mew0*(M+H);              #flux density(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M/10**9),\"*10**9 A/m\"\n",
+    "print \"flux density is\",round(B/10**6,4),\"*10**6 T\"\n",
+    "print \"answer for flux density given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetisation is 17725 A/m\n",
+      "answer for magnetisation given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "H=10**2;                  #magnetic field intensity(A/m)\n",
+    "B=0.0224;                  #flux density(T)\n",
+    "\n",
+    "#Calculations\n",
+    "M=(B/mew0)-H;              #magnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetisation is\",int(M),\"A/m\"\n",
+    "print \"answer for magnetisation given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "change in magnetic moment is 5.27 *10**-29 Am**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "r=5*10**-11;               #radius(m)\n",
+    "B=3;                       #flux density(T)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "mew=B*e**2*r**2/(4*m);     #change in magnetic moment(Am**2)\n",
+    "\n",
+    "#Result\n",
+    "print \"change in magnetic moment is\",round(mew*10**29,2),\"*10**-29 Am**2\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "susceptibility is 0.8 *10**-4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=200;          #temperature(K)\n",
+    "T2=300;          #temperature(K)\n",
+    "chi1=1.2*10**-4; #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "chi2=T1*chi1/T2;    #susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"susceptibility is\",chi2*10**4,\"*10**-4\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "paramagnetisation is 3.6 *10**2 A/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "H=10**5;                  #magnetic field intensity(A/m)\n",
+    "chi=3.6*10**-3;            #susceptibility\n",
+    "\n",
+    "#Calculations\n",
+    "M=chi*H;                   #paramagnetisation(A/m)\n",
+    "\n",
+    "#Result\n",
+    "print \"paramagnetisation is\",M/10**2,\"*10**2 A/m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "magnetic moment is 5.655 *10**-24 Am**2\n",
+      "saturation magnetic induction is 6.5 *10**-4 T\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "mewB=9.27*10**-24;         \n",
+    "rho=8906;                  #density(kg/m**3)\n",
+    "N=6.023*10**23;            #avagadro number\n",
+    "W=58.7;                    #atomic weight\n",
+    "\n",
+    "#Calculations\n",
+    "mewM=0.61*mewB;            #magnetic moment(Am**2)\n",
+    "B=rho*N*mew0*mewM/W;       #saturation magnetic induction(T)\n",
+    "\n",
+    "#Result\n",
+    "print \"magnetic moment is\",round(mewM*10**24,3),\"*10**-24 Am**2\"\n",
+    "print \"saturation magnetic induction is\",round(B*10**4,1),\"*10**-4 T\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 423"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "diamagnetic susceptibility is -8.249 *10**-8\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "mew0=4*math.pi*10**-7;     #permeability of vacuum\n",
+    "e=1.6*10**-19;             #charge(coulomb)\n",
+    "m=9.1*10**-31;             #mass(kg)\n",
+    "R=0.5*10**-10;             #radius(m)\n",
+    "N=28*10**26;               #number of atoms\n",
+    "Z=2;                       #atomic number\n",
+    "\n",
+    "#Calculations\n",
+    "chi_dia=-mew0*Z*e**2*N*R**2/(6*m);    #diamagnetic susceptibility\n",
+    "\n",
+    "#Result\n",
+    "print \"diamagnetic susceptibility is\",round(chi_dia*10**8,3),\"*10**-8\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yU7SECk.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yU7SECk.ipynb
new file mode 100644
index 00000000..fd167244
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yU7SECk.ipynb
@@ -0,0 +1,304 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 6: Schrodinger Wave Mechanics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 228"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy levels are 38 eV 150 eV 339 eV\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "a=10**-10;            #width(m)\n",
+    "h=6.62*10**-34;       #planck's constant\n",
+    "n1=1;\n",
+    "n2=2;\n",
+    "n3=3;\n",
+    "\n",
+    "#Calculation\n",
+    "Ex=h**2/(8*e*m*a**2);  #energy(eV)\n",
+    "E1=Ex*n1**2;         #energy at 1st level(eV)\n",
+    "E2=Ex*n2**2;         #energy at 2nd level(eV)\n",
+    "E3=Ex*n3**2;         #energy at 3rd level(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy levels are\",int(round(E1)),\"eV\",int(round(E2)),\"eV\",int(round(E3)),\"eV\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of finding the particle is 0.133\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "deltax=1*10**-10;        #width\n",
+    "a=15*10**-10;            #width(m)\n",
+    "\n",
+    "#Calculation\n",
+    "W=2*deltax/a;            #probability of finding the particle\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of finding the particle is\",round(W,3)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 229"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "probability of transmission of electron is 0.5\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=1;          #energy(eV)\n",
+    "V0=2;         #voltage(eV)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "e=1.6*10**-19;        #charge(coulomb)\n",
+    "chi=1.05*10**-34;     \n",
+    "a=2*10**-10;          #potential barrier\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(2*m*(V0-E)*e);\n",
+    "y=16*E*(1-(E/V0))/V0;\n",
+    "T=y*math.exp(-2*a*x/chi);     #probability of transmission of electron\n",
+    "\n",
+    "#Result\n",
+    "print \"probability of transmission of electron is\",round(T,1)\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 230"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 32,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons reflected is 0.38\n",
+      "fraction of electrons transmitted is 0.62\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.080*10**-19;          #energy(eV)\n",
+    "E_V0=0.016*10**-19;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "R=(x-y)/(x+y);       #fraction of electrons reflected\n",
+    "T=1-R;                    #fraction of electrons transmitted\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons reflected is\",round(R,2)\n",
+    "print \"fraction of electrons transmitted is\",round(T,2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12, Page number 231"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 37,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "fraction of electrons transmitted is 0.4998\n",
+      "fraction of electrons reflected is 0.5002\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=0.34;          #energy(eV)\n",
+    "E_V0=0.01;       #voltage(eV)\n",
+    "\n",
+    "#Calculation\n",
+    "x=math.sqrt(E);\n",
+    "y=math.sqrt(E_V0);\n",
+    "T=4*x*y/(x+y)**2;       #fraction of electrons transmitted \n",
+    "R=1-T;                  #fraction of electrons reflected\n",
+    "\n",
+    "#Result\n",
+    "print \"fraction of electrons transmitted is\",round(T,4)\n",
+    "print \"fraction of electrons reflected is\",round(R,4)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13, Page number 232"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 50,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "transmission coefficient is 3.27 *10**-9\n",
+      "transmission coefficient in 1st case is 7.62 *10**-8\n",
+      "transmission coefficient in 2nd case is 1.51 *10**-15\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19;  #charge(coulomb)\n",
+    "E1=1*e;         #energy(J)\n",
+    "E2=2*e;         #energy(J)\n",
+    "V0=5*e;         #voltage(J)\n",
+    "m=9.1*10**-31;        #mass of electron(kg)\n",
+    "chi=1.054*10**-34;     \n",
+    "a1=10*10**-10;         #potential barrier(m)\n",
+    "a2=20*10**-10;         #potential barrier(m)\n",
+    "\n",
+    "#Calculation\n",
+    "beta1=math.sqrt(2*m*(V0-E1)/(chi**2));\n",
+    "y1=16*E1*((V0-E1)/(V0**2));\n",
+    "T1=y1*math.exp(-2*a1*beta1);     #transmission coefficient\n",
+    "beta2=math.sqrt(2*m*(V0-E2)/(chi**2));\n",
+    "y2=16*E2*((V0-E2)/(V0**2));\n",
+    "T2=y2*math.exp(-2*a1*beta2);     #transmission coefficient in 1st case\n",
+    "T3=y2*math.exp(-2*a2*beta2);     #transmission coefficient in 2nd case\n",
+    "\n",
+    "#Result\n",
+    "print \"transmission coefficient is\",round(T1*10**9,2),\"*10**-9\"\n",
+    "print \"transmission coefficient in 1st case is\",round(T2*10**8,2),\"*10**-8\"\n",
+    "print \"transmission coefficient in 2nd case is\",round(T3*10**15,2),\"*10**-15\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yZCyjq6.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yZCyjq6.ipynb
new file mode 100644
index 00000000..72f70169
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yZCyjq6.ipynb
@@ -0,0 +1,540 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 3: Inadequacy of Classical Physics"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum energy of photoelectron is 3.038 *10**-19 J\n",
+      "maximum velocity of electron is 8.17 *10**5 ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=1700*10**-10;       #wavelength(m)\n",
+    "lamda0=2300*10**-10;      #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "KE=h*c*((1/lamda)-(1/lamda0));       #maximum energy of photoelectron(J)\n",
+    "vmax=math.sqrt(2*KE/me);             #maximum velocity of electron(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"maximum energy of photoelectron is\",round(KE*10**19,3),\"*10**-19 J\"\n",
+    "print \"maximum velocity of electron is\",round(vmax/10**5,2),\"*10**5 ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 128"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "threshold wavelength is 5380 angstrom\n",
+      "since wavelength of orange light is more, photoelectric effect doesn't take place\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=2.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=6850;               #wavelength of orange light(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda0=h*c/W;             #threshold wavelength(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"threshold wavelength is\",int(lamda0*10**10),\"angstrom\"\n",
+    "print \"since wavelength of orange light is more, photoelectric effect doesn't take place\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "retarding potential is 1.175 volts\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "W=1.3*e;                  #work function(J)\n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "new=6*10**14;             #frequency(Hertz)\n",
+    "\n",
+    "#Calculations\n",
+    "V0=((h*new)-W)/e;         #retarding potential(volts)\n",
+    "\n",
+    "#Result\n",
+    "print \"retarding potential is\",V0,\"volts\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "work function is 1.28 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=3*10**-7;           #wavelength(m)\n",
+    "me=9.1*10**-31;           #mass of electron(kg)\n",
+    "v=1*10**6;                #velocity(m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "W=(h*c/lamda)-(me*v**2/2);      #work function(J)\n",
+    "W=W/e;                          #work function(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"work function is\",round(W,2),\"eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 129"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "photoelectric current is 1.86 micro ampere\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;            #planks constant(Js)\n",
+    "e=1.6*10**-19;            #charge(coulomb)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda=4600*10**-10;       #wavelength(m)\n",
+    "qe=0.5;                   #efficiency(%)\n",
+    "\n",
+    "#Calculations\n",
+    "E=h*c/lamda;              #energy(J)\n",
+    "n=10**-3/E;               #number of photons/second\n",
+    "i=n*qe*e*10**6/100;       #photoelectric current(micro ampere)\n",
+    "\n",
+    "#Result\n",
+    "print \"photoelectric current is\",round(i,2),\"micro ampere\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 130"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "planck's constant is 6.61 *10**-34 joule second\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "T1=3*10**-19;             #temperature(J)\n",
+    "T2=1*10**-19;             #temperature(J)\n",
+    "c=3*10**8;                #velocity(m/sec)\n",
+    "lamda1=3350;              #wavelength(m)\n",
+    "lamda2=5060;              #wavelength(m)\n",
+    "\n",
+    "#Calculations\n",
+    "x=10**10*((1/lamda1)-(1/lamda2));\n",
+    "h=(T1-T2)/(c*x);          #planck's constant(joule second)\n",
+    "\n",
+    "#Result\n",
+    "print \"planck's constant is\",round(h*10**34,2),\"*10**-34 joule second\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 131"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 3.0121 angstrom\n",
+      "energy of recoil electron is 2.66 *10**-18 joule\n",
+      "answers given in the book are wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=60*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(angstrom)\n",
+    "lamda_dash=3.058;        #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "lamda_dash=round(lamda_dash*10**10,4)*10**-10;     #wavelength of scattered radiation(m)\n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash*10**10,\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**18,2),\"*10**-18 joule\"\n",
+    "print \"answers given in the book are wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 132"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 2.003 angstrom\n",
+      "velocity of recoil electron is 0.0188 *10**8 ms-1\n",
+      "answer for velocity given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=30*math.pi/180;    #angle(radian)\n",
+    "lamda=2*10**-10;         #wavelength(angstrom)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda_sr=h/(m0*c);   \n",
+    "lamda_dash=lamda+(lamda_sr*(1-math.cos(theta)));   #wavelength of scattered radiation(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=1+(E/(m0*c**2));\n",
+    "v=c*math.sqrt(1-((1/x)**2));                       #velocity of recoil electron(m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"velocity of recoil electron is\",round(v/10**8,4),\"*10**8 ms-1\"\n",
+    "print \"answer for velocity given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 133"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 49,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered photon is 3.024 angstrom\n",
+      "energy of recoil electron is 0.5 *10**-17 joules\n",
+      "direction of recoil electron is 44 degrees 46 minutes\n",
+      "answer for angle given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "lamda=3*10**-10;         #wavelength(m)   \n",
+    "\n",
+    "#Calculations\n",
+    "lamda_dash=lamda+(h*(1-math.cos(theta))/(m0*c));   #wavelength of scattered photon(m)    \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));                  #energy of recoil electron(joule)\n",
+    "x=h/(lamda*m0*c);\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered photon is\",round(lamda_dash*10**10,3),\"angstrom\"\n",
+    "print \"energy of recoil electron is\",round(E*10**17,1),\"*10**-17 joules\"\n",
+    "print \"direction of recoil electron is\",int(phi),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for angle given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10, Page number 134"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 51,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy of scattered photon is 0.226 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.62*10**-34;          #planks constant(Js)\n",
+    "theta=180*math.pi/180;   #angle(radian)\n",
+    "E=1.96*10**6*e;          #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=2*h/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;   #wavelength of scattered photon(m)    \n",
+    "Edash=h*c/(e*lamda_dash);       #energy of scattered photon(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"energy of scattered photon is\",round(Edash/10**6,3),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11, Page number 135"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 65,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "wavelength of scattered radiation is 4.9e-12 m\n",
+      "energy of recoil electron is 3.9592 *10**-14 Joules\n",
+      "direction of recoil electron is 27 degrees 47 minutes\n",
+      "answer for energy and direction of recoil electron and given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "c=3*10**8;               #velocity of light(m/sec)\n",
+    "e=1.6*10**-19;           #charge(coulomb)\n",
+    "m0=9.1*10**-31;          #mass(kg)\n",
+    "h=6.6*10**-34;           #planks constant(Js)\n",
+    "theta=90*math.pi/180;    #angle(radian)\n",
+    "E=500*10**3*e;           #energy of scattered photon(J)\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=h*c/E;             #wavelength(m)\n",
+    "delta_lamda=h*(1-math.cos(theta))/(m0*c);   \n",
+    "lamda_dash=lamda+delta_lamda;           #wavelength of scattered radiation(m) \n",
+    "lamda_dash=round(lamda_dash*10**12,1)*10**-12;   #wavelength of scattered radiation(m) \n",
+    "E=h*c*((1/lamda)-(1/lamda_dash));       #energy of recoil electron(J)\n",
+    "tanphi=lamda*math.sin(theta)/(lamda_dash-(lamda*math.cos(theta)));\n",
+    "phi=math.atan(tanphi);                             #direction of recoil electron(radian)\n",
+    "phi=phi*180/math.pi;                               #direction of recoil electron(degrees)\n",
+    "phim=60*(phi-int(phi));                            #angle(minutes)\n",
+    "\n",
+    "#Result\n",
+    "print \"wavelength of scattered radiation is\",lamda_dash,\"m\"\n",
+    "print \"energy of recoil electron is\",round(E*10**14,4),\"*10**-14 Joules\"\n",
+    "print \"direction of recoil electron is\",int(round(phi)),\"degrees\",int(phim),\"minutes\"\n",
+    "print \"answer for energy and direction of recoil electron and given in the book is wrong\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yrMGHYH.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yrMGHYH.ipynb
new file mode 100644
index 00000000..171aaa2d
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_yrMGHYH.ipynb
@@ -0,0 +1,396 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 5: Uncertainity Principle"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 0.211 *10**-20 kg m/sec\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "hby2pi=1.055*10**-34;      #plancks constant(J s)\n",
+    "deltax=5*10**-14;          #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "delta_px=hby2pi/deltax;    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",delta_px*10**20,\"*10**-20 kg m/sec\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 3.85 *10**-3 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.6*10**-34;      #plancks constant(J s)\n",
+    "m=9.1*10**-31;      #mass(kg)\n",
+    "v=600;              #speed(m/s)\n",
+    "deltap=(0.005/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**3,2),\"*10**-3 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in momentum is 3.5 *10**-24 kg ms-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=3*10**-11;    #uncertainity(m)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);    #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in momentum is\",round(deltap*10**24,1),\"*10**-24 kg ms-1\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in determination of energy is 6.59 *10**-8 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltat=10**-8;       #lifetime of excited atom(sec)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltaE=h/(2*math.pi*deltat*e);    #uncertainity in determination of energy(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in determination of energy is\",round(deltaE*10**8,2),\"*10**-8 eV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in measurement of angular momentum is 2.17 *10**-29 Js\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltaphi=math.pi/(180*60*60);      \n",
+    "\n",
+    "#Calculations\n",
+    "deltaL=h/(2*math.pi*deltaphi);    #uncertainity in measurement of angular momentum(Js)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in measurement of angular momentum is\",round(deltaL*10**29,2),\"*10**-29 Js\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in position is 5.27 *10**-34 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "m=25*10**-3;         #mass(kg)\n",
+    "v=400;               #speed(m/s)\n",
+    "deltap=(2/100)*m*v;  #uncertainity in momentum(kg m/sec)\n",
+    "\n",
+    "#Calculations\n",
+    "deltax=h/(2*math.pi*deltap);    #uncertainity in position(m)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in position is\",round(deltax*10**34,2),\"*10**-34 m\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7, Page number 181"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "percentage of uncertainity in momentum is 3.1 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=2*10**-10;    #uncertainity in position(m)\n",
+    "m=9.1*10**-31;       #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "V=1000;              #voltage(V)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #uncertainity in momentum(kg m/s)\n",
+    "p=math.sqrt(2*m*e*V);             #momentum(kg m/s)\n",
+    "pp=deltap*100/p;                  #percentage of uncertainity in momentum\n",
+    "\n",
+    "#Result\n",
+    "print \"percentage of uncertainity in momentum is\",round(pp,1),\"%\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "uncertainity in velocity of electron is 5.79 *10**4 ms-1\n",
+      "uncertainity in velocity of proton is 31.545 ms-1\n",
+      "answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=20*10**-10;   #uncertainity in position(m)\n",
+    "me=9.1*10**-31;      #mass of electron(kg)\n",
+    "mp=1.67*10**-27;     #mass of proton(kg)\n",
+    "\n",
+    "#Calculations\n",
+    "deltave=h/(2*math.pi*deltax*me);      #uncertainity in velocity of electron(ms-1)\n",
+    "deltavp=h/(2*math.pi*deltax*mp);      #uncertainity in velocity of proton(ms-1)\n",
+    "\n",
+    "#Result\n",
+    "print \"uncertainity in velocity of electron is\",round(deltave*10**-4,2),\"*10**4 ms-1\"\n",
+    "print \"uncertainity in velocity of proton is\",round(deltavp,3),\"ms-1\"\n",
+    "print \"answer for uncertainity in velocity of proton given in the book varies due to rounding off errors\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9, Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "minimum uncertainity in momentum is 1.3 *10**-20 kg m/s\n",
+      "minimum kinetic energy of proton is 0.32 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration  \n",
+    "h=6.62*10**-34;      #plancks constant(J s)\n",
+    "deltax=8*10**-15;    #uncertainity in position(m)\n",
+    "mp=1.67*10**-27;     #mass(kg)\n",
+    "e=1.6*10**-19;       #charge(coulomb)\n",
+    "\n",
+    "#Calculations\n",
+    "deltap=h/(2*math.pi*deltax);      #minimum uncertainity in momentum(kg m/s)\n",
+    "ke=deltap**2/(2*mp*e);            #minimum kinetic energy of proton(eV)\n",
+    "\n",
+    "#Result\n",
+    "print \"minimum uncertainity in momentum is\",round(deltap*10**20,1),\"*10**-20 kg m/s\"\n",
+    "print \"minimum kinetic energy of proton is\",round(ke/10**6,2),\"MeV\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zKQXNUB.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zKQXNUB.ipynb
new file mode 100644
index 00000000..31b7323a
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zKQXNUB.ipynb
@@ -0,0 +1,277 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 7: Nuclear Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "radius of He is 2.2375 fermi\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A1=165;               #mass number\n",
+    "A2=4;                 #mass number\n",
+    "R1=7.731;             #radius(fermi)\n",
+    "\n",
+    "#Calculation\n",
+    "R2=R1*(A2/A1)**(1/3);     #radius of He(fermi)\n",
+    "\n",
+    "#Result\n",
+    "print \"radius of He is\",round(R2,4),\"fermi\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average binding energy per nucleon is 7.07 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "alpha=4.00150;        #mass of alpha particle(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=2*(p+n)-alpha;\n",
+    "BE=deltam*m;          #binding energy(MeV)\n",
+    "ABE=BE/4;             #average binding energy per nucleon(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"average binding energy per nucleon is\",round(ABE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 7.25 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Li36=6.015125;        #mass of Li(amu)\n",
+    "Li37=7.016004;        #mass of Li(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Li36+n-Li37;   \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy released is 23.6 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "BEHe=4*7.0;        #binding energy for He\n",
+    "BEH=2*1.1;         #binding energy for H\n",
+    "\n",
+    "#Calculation\n",
+    "deltaE=BEHe-(2*BEH);     #energy released(MeV)   \n",
+    "\n",
+    "#Result\n",
+    "print \"energy released is\",deltaE,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "mass is 19.987 amu\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "BE=160.647;           #binding energy(MeV)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "Mx=10*(p+n)-(BE/m);   #mass(amu)\n",
+    "\n",
+    "#Result\n",
+    "print \"mass is\",round(Mx,3),\"amu\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 261"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 11.471 MeV\n",
+      "answer given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Ca41=40.962278;       #mass of Ca(amu)\n",
+    "Ca42=41.958622;       #mass of Ca(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Ca41+n-Ca42;     \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,3),\"MeV\"\n",
+    "print \"answer given in the book varies due to rounding off errors\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zYPve8I.ipynb b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zYPve8I.ipynb
new file mode 100644
index 00000000..31b7323a
--- /dev/null
+++ b/Physics_BSc(Paper_4)_by_Sanjeeva_Rao,_Bhikshmaiah,_Ramakrishna_Reddy,_Ananta_Ramaiah/C_zYPve8I.ipynb
@@ -0,0 +1,277 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 7: Nuclear Structure"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "radius of He is 2.2375 fermi\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A1=165;               #mass number\n",
+    "A2=4;                 #mass number\n",
+    "R1=7.731;             #radius(fermi)\n",
+    "\n",
+    "#Calculation\n",
+    "R2=R1*(A2/A1)**(1/3);     #radius of He(fermi)\n",
+    "\n",
+    "#Result\n",
+    "print \"radius of He is\",round(R2,4),\"fermi\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2, Page number 259"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "average binding energy per nucleon is 7.07 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "alpha=4.00150;        #mass of alpha particle(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=2*(p+n)-alpha;\n",
+    "BE=deltam*m;          #binding energy(MeV)\n",
+    "ABE=BE/4;             #average binding energy per nucleon(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"average binding energy per nucleon is\",round(ABE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 7.25 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Li36=6.015125;        #mass of Li(amu)\n",
+    "Li37=7.016004;        #mass of Li(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Li36+n-Li37;   \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,2),\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "energy released is 23.6 MeV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "BEHe=4*7.0;        #binding energy for He\n",
+    "BEH=2*1.1;         #binding energy for H\n",
+    "\n",
+    "#Calculation\n",
+    "deltaE=BEHe-(2*BEH);     #energy released(MeV)   \n",
+    "\n",
+    "#Result\n",
+    "print \"energy released is\",deltaE,\"MeV\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5, Page number 260"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "mass is 19.987 amu\n",
+      "answer given in the book is wrong\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "p=1.007276;           #mass of proton(amu)\n",
+    "BE=160.647;           #binding energy(MeV)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "Mx=10*(p+n)-(BE/m);   #mass(amu)\n",
+    "\n",
+    "#Result\n",
+    "print \"mass is\",round(Mx,3),\"amu\"\n",
+    "print \"answer given in the book is wrong\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6, Page number 261"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "binding energy of neutron is 11.471 MeV\n",
+      "answer given in the book varies due to rounding off errors\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n=1.008665;           #mass of neutron(amu)\n",
+    "Ca41=40.962278;       #mass of Ca(amu)\n",
+    "Ca42=41.958622;       #mass of Ca(amu)\n",
+    "m=931;                \n",
+    "\n",
+    "#Calculation\n",
+    "deltam=Ca41+n-Ca42;     \n",
+    "BE=deltam*m;          #binding energy of neutron(MeV)\n",
+    "\n",
+    "#Result\n",
+    "print \"binding energy of neutron is\",round(BE,3),\"MeV\"\n",
+    "print \"answer given in the book varies due to rounding off errors\""
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter10_jNQZCoy.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter10_jNQZCoy.ipynb
new file mode 100644
index 00000000..a26284d9
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter10_jNQZCoy.ipynb
@@ -0,0 +1,544 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 10 : Opto-electronic Devices"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.1 , Page number 385"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Thickness of silicon= 0.016 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "alpha=10**2 #absorption coefficient in cm^-1\n",
+    "absorption=0.2 #80% absorption represented in decimal format\n",
+    "\n",
+    "#Calculations\n",
+    "d=(1/alpha)*math.log(1/absorption)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Thickness of silicon= %.3f cm\" %d)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.2 , Page number 385"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "open-circuit voltage Voc= 0.541 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=3*10**18 #in cm^-3\n",
+    "Nd=2*10**16 #in cm^-3\n",
+    "Dn=25 #in cm**2/s\n",
+    "Dp=10 #in cm**2/s\n",
+    "tau_n0=4*10**-7 #in s\n",
+    "tau_p0=10**-7 #in s\n",
+    "JL=20*10**-3 #photocurrent density in mA/cm**2\n",
+    "T=300 #in K\n",
+    "ni=1.5*10**10 #in cm^-3\n",
+    "e=1.6*10**-19 #in Joules\n",
+    "Const=0.026 #constant for KT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Ln=math.sqrt(Dn*tau_n0) #in micro-m\n",
+    "Lp=math.sqrt(Dp*tau_p0) #in micro-m\n",
+    "JS=e*ni**2*((Dn/(Ln*Na))+(Dp/(Lp*Nd))) #reverse saturation current density in A/cm**2\n",
+    "Voc=Const*math.log(1+(JL/JS))\n",
+    "\n",
+    "#Result\n",
+    "print(\"open-circuit voltage Voc= %0.3f V\" %Voc)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.3 , Page number 399"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Gain of the photoconductor= 686.4\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "L=80*10**-4 #length in m\n",
+    "myu_n=1350 #in cm**2/V\n",
+    "myu_p=480 #in cm**2/V\n",
+    "V=12 #applied voltage in V\n",
+    "tau_n=3.95*10**-9 #transit time in sec\n",
+    "tau_p=2*10**-6 #carrier lifetime in sec\n",
+    "\n",
+    "#Calculations\n",
+    "tn=L**2/(myu_n*V) #transit time in sec\n",
+    "Gph=(tau_p/tau_n)*(1+(myu_p/myu_n))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Gain of the photoconductor= %3.1f\" %Gph)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.4 , Page number 400"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "steady-state photocurrent density= 0.43 A/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=5*10**16 #in cm**3\n",
+    "Nd=5*10**16 #in cm**3\n",
+    "Dn=25 #in cm**2/s\n",
+    "Dp=10 #in cm**2/s\n",
+    "tau_n0=6*10**-7 #in s\n",
+    "tau_p0=2*10**-7 #in s\n",
+    "VR=6 #in V\n",
+    "GL=5*10**20 #in cm^-3/s\n",
+    "ni=1.5*10**10 #in cm^-3\n",
+    "e=1.6*10**-19 #in Joules\n",
+    "epsilon_s=11.7*8.85*10**-14 #in F/cm\n",
+    "Const=0.026 #constant for KT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Ln=math.sqrt(Dn*tau_n0) #in mico-m\n",
+    "Lp=math.sqrt(Dp*tau_p0) #in micro-m\n",
+    "Vbi=Const*math.log((Na*Nd)/ni**2) #in V\n",
+    "W=(((2*epsilon_s)/e)*((Na+Nd)/(Na*Nd))*(Vbi+VR))**0.5 #in micro-m\n",
+    "JL=e*GL*(W+Ln+Lp) #photocurrent density\n",
+    "\n",
+    "#Result\n",
+    "print(\"steady-state photocurrent density= %0.2f A/cm**2\" %JL)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.5 , Page number 401"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Critical angle for GaAs-air interface= 15.9 degrees\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n1=1 \n",
+    "n2=3.66\n",
+    "\n",
+    "#Calculations\n",
+    "theta_c=math.asin(n1/n2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Critical angle for GaAs-air interface= %2.1f degrees\" %math.degrees(theta_c))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.6 , Page number 402"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "electron concentration= 1e+15 cm^-3\n",
+      "\n",
+      "hole concentration= 2.1e+05 cm^-3\n",
+      "\n",
+      "Fermi level w.r.t intrinsic fermi level= 0.279 eV\n",
+      "\n",
+      "b)\n",
+      "electron concentration= 1e+15 cm^-3\n",
+      "\n",
+      "hole concentration= 1e+12 cm^-3\n",
+      "\n",
+      "Quasi fermi level for n-type carrier= 0.279 eV\n",
+      "\n",
+      "Quasi fermi level for p-type carrier= 0.11 eV\n",
+      "\n",
+      "c)\n",
+      "electron concentration= 1e+18 cm^-3\n",
+      "\n",
+      "hole concentration= 1e+18 cm^-3\n",
+      "\n",
+      "Quasi fermi level for n-type carrier= 0.45 eV\n",
+      "\n",
+      "Quasi fermi level for p-type carrier= 0.45 eV\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=10**15 #donor atoms in cm^-3\n",
+    "ni=1.45*10**10 #in cm^-3\n",
+    "k=8.62*10**-5 #in eV/K\n",
+    "T=300 #in K\n",
+    "Const=0.025 #coonstant for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "n=10**15 #in cm^-3\n",
+    "p=ni**2/Nd #in cm^-3\n",
+    "delE=Const*math.log(n/ni) #in eV\n",
+    "\n",
+    "#b)\n",
+    "n0=10**15 #in cm^-3\n",
+    "p0=10**12 #in cm^-3\n",
+    "delE_fni=Const*math.log(n0/ni) #in eV\n",
+    "delE_ifp=Const*math.log(p0/ni) #in eV\n",
+    "\n",
+    "#c)\n",
+    "n1=10**18 #in cm^-3\n",
+    "p1=10**18 #in cm^-3\n",
+    "delE_fni1=Const*math.log(n1/ni) #in eV\n",
+    "delE_ifp1=Const*math.log(p1/ni) #in eV\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\nelectron concentration= %.1g cm^-3\\n\" %n)\n",
+    "print(\"hole concentration= %.2g cm^-3\\n\" %p)\n",
+    "print(\"Fermi level w.r.t intrinsic fermi level= %0.3f eV\\n\" %delE)\n",
+    "print(\"b)\\nelectron concentration= %.1g cm^-3\\n\" %n0)\n",
+    "print(\"hole concentration= %.1g cm^-3\\n\" %p0)\n",
+    "print(\"Quasi fermi level for n-type carrier= %0.3f eV\\n\" %delE_fni)\n",
+    "print(\"Quasi fermi level for p-type carrier= %0.2f eV\\n\" %delE_ifp)\n",
+    "print(\"c)\\nelectron concentration= %.1g cm^-3\\n\" %n1)\n",
+    "print(\"hole concentration= %.1g cm^-3\\n\" %p1)\n",
+    "print(\"Quasi fermi level for n-type carrier= %0.2f eV\\n\" %delE_fni1)\n",
+    "print(\"Quasi fermi level for p-type carrier= %0.2f eV\\n\" %delE_ifp1)\n",
+    "#The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.7 , Page number 403"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 24,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Wavelength of radiation for germanium= 1.85 micro-m\n",
+      "\n",
+      "Wavelength of radiation for silicon= 1.10 micro-m\n",
+      "\n",
+      "Wavelength of radiation for gallium-arsenide= 0.87 micro-m\n",
+      "\n",
+      "Wavelength of radiation for SiO2= 0.14 micro-m\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "h=4.135*10**-15 #plancks constant in eVs\n",
+    "c=3*10**8 #in m/s\n",
+    "EgGe=0.67 #in eV\n",
+    "EgSi=1.124 #in eV\n",
+    "EgGaAs=1.42 #in eV\n",
+    "EgSiO2=9 #in eV\n",
+    "\n",
+    "#Calculations\n",
+    "lamda1=(h*c)/EgGe/10**-6 #in micro-m\n",
+    "lamda2=(h*c)/EgSi/10**-6 #in micro-m\n",
+    "lamda3=(h*c)/EgGaAs/10**-6 #in micro-m\n",
+    "lamda4=(h*c)/EgSiO2/10**-6 #in micro-m\n",
+    "\n",
+    "#Result\n",
+    "print(\"Wavelength of radiation for germanium= %1.2f micro-m\\n\" %lamda1)\n",
+    "print(\"Wavelength of radiation for silicon= %1.2f micro-m\\n\" %lamda2) #The answers vary due to round off error\n",
+    "print(\"Wavelength of radiation for gallium-arsenide= %1.2f micro-m\\n\" %lamda3)\n",
+    "print(\"Wavelength of radiation for SiO2= %1.2f micro-m\\n\" %lamda4)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.8 , Page number 404"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)Current= 5.59*10**-15 A\n",
+      "\n",
+      "b)Total number of solar cells= 25000\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=10**18 #in cm**-3\n",
+    "Nd=10**17 #in cm**-3\n",
+    "myu_p=471 #in cm**2/Vs\n",
+    "myu_n=1417 #in cm**2/Vs\n",
+    "tau_p=10**-8 #in s\n",
+    "tau_n=10**-6 #in s \n",
+    "JL=40 #in mA/cm**2\n",
+    "A=10**-5 #in cm**2\n",
+    "R1=1000 #in ohm\n",
+    "e=1.6*10**-19 #in J\n",
+    "ni=1.45*10**10 #in cm**-3\n",
+    "Vt=0.02586 #constant for kT/e at 300K in V\n",
+    "V=0.1 #in V\n",
+    "n=10 #number of solar cells\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "Dp=Vt*myu_p #in cm**2/s\n",
+    "Dn=Vt*myu_n #in cm**2/s\n",
+    "Ln=math.sqrt(Dn*tau_n) #in cm\n",
+    "Lp=math.sqrt(Dp*tau_p) #in cm\n",
+    "Js=e*ni**2*((Dp/(Nd*Lp))+(Dn/(Na*Ln))) #in A/cm**2\n",
+    "Is=Js*10**-5 #in A\n",
+    "IF=Is*(math.exp(V/Vt)-1) #in A\n",
+    "\n",
+    "#b)\n",
+    "IL=40*10**-8 #in A\n",
+    "I=IL-IF #in \n",
+    "X=((10**-3)/(I))*n\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)Current= %.2f*10**-15 A\\n\" %round(IF/10**-15,2)) #The answers vary due to round off error\n",
+    "print(\"b)Total number of solar cells= %i\" %X)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.9 , Page number 405"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Wavelength= 8.69*10**-7 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Eg=1.43 #Energy band gap in eV\n",
+    "h=4.14*10**-15 #planck's constant in eV/s\n",
+    "c=3*10**8 #in m/s\n",
+    "\n",
+    "#Calculations\n",
+    "lamda=(h*c)/Eg\n",
+    "\n",
+    "#Result\n",
+    "print(\"Wavelength= %0.2f*10**-7 m\" %round(lamda/10**-7,2)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 10.10 , Page number 406"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 49,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Power conversion efficiency = 0.32 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "PC=190 #optical Power generated in mW\n",
+    "I=25*10**-3 #in A\n",
+    "V=1.5 #in V\n",
+    "\n",
+    "#Calculations\n",
+    "P=V/I #Electrical Power\n",
+    "n=PC/P\n",
+    "\n",
+    "#Result\n",
+    "print(\"Power conversion efficiency = %0.2f %%\" %(n/10))\n",
+    "#The answer provided in the textbook is wrong"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter11_xIicyr8.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter11_xIicyr8.ipynb
new file mode 100644
index 00000000..2cd846f8
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter11_xIicyr8.ipynb
@@ -0,0 +1,398 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 11 : Power Devices"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.1 , Page number 4420"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "maximum collector current= 3.75 A\n",
+      "\n",
+      "Maximum collector-emiiter voltage= 30 V\n",
+      "\n",
+      "Maximum Power rating= 28.12 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "RL=8 #in ohm\n",
+    "VCC=30 #in V\n",
+    "\n",
+    "#Calculations\n",
+    "IC_max=VCC/RL \n",
+    "VCE_max=VCC\n",
+    "IC=VCC/(2*RL)\n",
+    "VCE=VCC-(IC*RL)\n",
+    "PT=VCE*IC\n",
+    "\n",
+    "#Result\n",
+    "print(\"maximum collector current= %1.2f A\\n\" %IC_max)\n",
+    "print(\"Maximum collector-emiiter voltage= %i V\\n\" %VCE_max)\n",
+    "print(\"Maximum Power rating= %2.2f W\" %PT) "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.2 , Page number 421"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Drain Resistance= 6.25 ohm\n",
+      "\n",
+      "Drain current at maximum power ditribution point= 2 A\n",
+      "\n",
+      "Drain-to-source voltage at maximum power dissipation point= 12.5 V\n",
+      "\n",
+      "Maximum power dissipation= 25 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "VDD=25 #voltage axis intersection point in V\n",
+    "ID=4 #current in A\n",
+    "\n",
+    "#Calculations\n",
+    "RD=VDD/ID\n",
+    "ID=VDD/(2*RD)\n",
+    "VDS=VDD-(ID*RD)\n",
+    "PT=VDS*ID\n",
+    "\n",
+    "#Result\n",
+    "print(\"Drain Resistance= %1.2f ohm\\n\" %RD)\n",
+    "print(\"Drain current at maximum power ditribution point= %i A\\n\" %ID)\n",
+    "print(\"Drain-to-source voltage at maximum power dissipation point= %2.1f V\\n\" %VDS)\n",
+    "print(\"Maximum power dissipation= %i W\" %PT)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.3 , Page number 422"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "net common-emitter current gain= 440\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "beta1=20 #bjt gain\n",
+    "beta2=20 #bjt gain\n",
+    "\n",
+    "#Calculations\n",
+    "beta0=beta1+beta2+(beta1*beta2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"net common-emitter current gain= %i\" %beta0) #The answer in the textbook is mathematically incorrect"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.4 , Page number 91"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Case(a):No heat sink used :-Maximum power distribution= 2.95 W\n",
+      "\n",
+      "Case(b):Heaat sink used :- Maximum power distribution= 18.36 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "TJ_max=150 #in C\n",
+    "Tamb=27 #in C\n",
+    "Rth_dp=1.7 #Thermal resistance in C/W\n",
+    "Rth_pa=40 #in C/W\n",
+    "Rth_ps=1 #in C/W\n",
+    "Rth_sa=4 #in C/W\n",
+    "\n",
+    "#Calculations\n",
+    "PD1_max=(TJ_max-Tamb)/(Rth_dp+Rth_pa)\n",
+    "PD2_max=(TJ_max-Tamb)/(Rth_dp+Rth_sa+Rth_ps)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Case(a):No heat sink used :-Maximum power distribution= %1.2f W\\n\" %PD1_max)\n",
+    "print(\"Case(b):Heaat sink used :- Maximum power distribution= %2.2f W\" %PD2_max)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.5 , Page number 436"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Total power dissipation= 240.6 W\n",
+      "The BJT is working outside the SOA\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "B=10 #current gain\n",
+    "IB=0.6 #in A\n",
+    "VBE=1 #in V\n",
+    "RC=10 #in ohm\n",
+    "VCC=100 #in Vs\n",
+    "\n",
+    "#Calculations\n",
+    "IC=B*IB #in A\n",
+    "VCE=VCC-(IC*RC) #in V\n",
+    "VCB=VCE-VBE #in V\n",
+    "PT=(VCE*IC)+(VBE*IB)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Total power dissipation= %.1f W\" %PT)\n",
+    "print(\"The BJT is working outside the SOA\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.6 , Page number 437"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Emitter current= 12.55 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Beff=250 #effective gain\n",
+    "B1=25 #current gain of transistor\n",
+    "B2=8.65 #effective gain of Darlington-pair\n",
+    "iB=50*10**-3 #in A\n",
+    "\n",
+    "#Calculations\n",
+    "iC2=iB*(Beff-B1)\n",
+    "iE2=(1+(1/B2))*iC2\n",
+    "\n",
+    "#Result\n",
+    "print(\"Emitter current= %2.2f A\" %iE2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.7 , Page number 438"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "peak-point voltage= 9.7 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "VBB=24 #in V\n",
+    "r1=3 #in k-ohm\n",
+    "r2=5 #in k-ohm\n",
+    "\n",
+    "#Calculations\n",
+    "n=r1/(r1+r2)\n",
+    "VP=(n*VBB)+0.7\n",
+    "\n",
+    "#Result\n",
+    "print(\"peak-point voltage= %1.1f V\" %VP)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 11.8 , Page number 437"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Actual power dissipation= 12.23 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Rth_sink=4 #resistance in C/W\n",
+    "Rth_case=1.5 #in C/W\n",
+    "T2=200 #Temperature in C\n",
+    "T1=27 #Room temperature in C\n",
+    "P=20 #power in W\n",
+    "\n",
+    "#Calculations\n",
+    "Rth=(T2-T1)/P\n",
+    "Tdev=T2\n",
+    "Tamb=T1\n",
+    "Rth_dp=Rth \n",
+    "Rth_ps=Rth_case #case-sink resistance\n",
+    "Rth_sa=Rth_sink #sink-ambient resistance\n",
+    "PD=(Tdev-Tamb)/(Rth_dp+Rth_ps+Rth_sa)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Actual power dissipation= %2.2f W\" %PD) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter12_1G5pKOe.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter12_1G5pKOe.ipynb
new file mode 100644
index 00000000..2c961102
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter12_1G5pKOe.ipynb
@@ -0,0 +1,159 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 12 : INTEGRATED CIRCUITS AND MICRO-ELECTROMECHANICAL SYSTEM"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12.1 , Page number 456"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Effective Resistance= 10.17 k-ohm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "l=100 #length of resistor in micro-m\n",
+    "w=10 #width of resistor in micro-m\n",
+    "R=0.9 #sheet resistance in k-ohm/n \n",
+    "End_points=0.65*2 #Total contribution of two end points\n",
+    "\n",
+    "#Calculations\n",
+    "Total_squares=l/w\n",
+    "T=Total_squares+End_points #Total effective sqaures\n",
+    "Reff=T*R\n",
+    "\n",
+    "#Result\n",
+    "print(\"Effective Resistance= %0.2f k-ohm\" %Reff)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12.2, Page number 457"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Capacitance per unit area = 0.69 pF/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "epsilon_i=3.9 #in F/cm\n",
+    "tox=0.5*10**-4 #in cm\n",
+    "\n",
+    "#Calculations\n",
+    "C=(epsilon_0*epsilon_i)/tox\n",
+    "\n",
+    "#Result\n",
+    "print(\"Capacitance per unit area = %0.2f pF/cm**2\" %round(C/10**-8,2))\n",
+    "#The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 12.3 , Page number 457"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Sheet resistance= 250 ohm\n",
+      "\n",
+      "average resistivity= 0.025 ohm-cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Length=4 #in micro-m\n",
+    "Width=1 #in micro-m\n",
+    "R=1000 #in ohm\n",
+    "xj=1*10**-4 #junction depth in cm                \n",
+    "\n",
+    "#Calculations\n",
+    "N=Length/Width\n",
+    "R0=R/N\n",
+    "rho=R0*xj\n",
+    "\n",
+    "#Result\n",
+    "print(\"Sheet resistance= %i ohm\\n\" %R0)\n",
+    "print(\"average resistivity= %0.3f ohm-cm\" %rho)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter1_gdrng9U.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter1_gdrng9U.ipynb
new file mode 100644
index 00000000..d6e53c88
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter1_gdrng9U.ipynb
@@ -0,0 +1,332 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 1 : Electron Dynamics "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.1 , Page number 8"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "The percentage change in mass of the electron is 4.2 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "V=20000 #potential in Volts\n",
+    "e=1.602*10**-19 #electronic charge in C\n",
+    "m=9.1*10**-31 #mass of electron in kg\n",
+    "c=3*10**8 #speed of light in m/s\n",
+    "\n",
+    "#Calculations\n",
+    "u=math.sqrt((2*V*e)/m) #speed u after acceleration through a potential V in m/s\n",
+    "mu=1/math.sqrt(1-(u/c)**2) #mass of electron moving with velocity mu in kg\n",
+    "delm=mu-1 #change in mass\n",
+    "\n",
+    "#Result\n",
+    "print(\"The percentage change in mass of the electron is %1.1f %%\" %(delm*100)) "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.2 , Page number 9"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "i)\n",
+      "Velocity with which the electrons strikes the plate = 11.87*10**6 m/s\n",
+      "ii)\n",
+      "Kinetic energy acquired by electron in joules = 6.408*10**-17 J\n",
+      "Kinetic energy acquired by electron in eV = 400\n",
+      "iii)\n",
+      "transit time in ns = 0.506\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "l=3*10**-3 #distance between two plate in meters\n",
+    "V=400 #potential difference in Volts\n",
+    "e=1.602*10**-19 #electronic charge in Joules\n",
+    "m=9.1*10**-31 #mass of electron in kg\n",
+    "\n",
+    "#Calculations\n",
+    "uB=math.sqrt((2*V*e)/m) #in m/s\n",
+    "KEJ=e*V #in  Joules\n",
+    "KEeV=int(e*V/(1.6*10**-19)) #in eV\n",
+    "tAB=(2*l/uB) #in ns\n",
+    "\n",
+    "#Result\n",
+    "print(\"i)\")\n",
+    "print(\"Velocity with which the electrons strikes the plate = %.2f*10**6 m/s\" %(uB/10**6))\n",
+    "print(\"ii)\")\n",
+    "print(\"Kinetic energy acquired by electron in joules = %.3f*10**-17 J\" %(KEJ/10**-17))\n",
+    "print(\"Kinetic energy acquired by electron in eV = %i\" %KEeV)\n",
+    "print(\"iii)\")\n",
+    "print(\"transit time in ns = %.3f\" %(tAB/10**-9))#The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.3 , Page number 26"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "radius of the circular path followed by electron is = 1.42*10**-2 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "B=0.02 #flux Density in Wb/m**2\n",
+    "u=5*10**7 #speed of electron in m/s\n",
+    "e=1.6*10**-19 #electronic charge Joules\n",
+    "m=9.1*10**-31 #mass of electron in kg                  \n",
+    "\n",
+    "#Calculations\n",
+    "r=(m*u)/(e*B) #in m\n",
+    "\n",
+    "#Result\n",
+    "print(\"radius of the circular path followed by electron is = %.2f*10**-2 m\" %(r/10**-2))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.4 , Page number 26"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Deflection Sensitivity = 4.5*10**-4 m/V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "L=3*10**-2 #length of plates in m\n",
+    "d=4*10**-3 #spacing betweenn plates in m\n",
+    "l=30*10**-2 #distance in m\n",
+    "V1=2500 #potential in V\n",
+    "\n",
+    "#Calculations\n",
+    "Se=(L*l)/(2*d*V1)/10**-4\n",
+    "\n",
+    "#Result\n",
+    "print(\"Deflection Sensitivity = %1.1f*10**-4 m/V\" %Se)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.5 , Page number 27"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Acceleration of the electron is = -5.3*10**15 m/s**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ey=3*10**4 #electric field in y-axis in N/C\n",
+    "Ex=0      #electric field in x-axis in N/C\n",
+    "q=1.6*10**-19 #electric charge in C\n",
+    "me=9.1*10**-31 #in kg\n",
+    "\n",
+    "#Calculations\n",
+    "#F=q*E\n",
+    "Fy=-q*Ey #Force in y direction \n",
+    "ay=Fy/me\n",
+    "\n",
+    "#Result\n",
+    "print(\"Acceleration of the electron is = %.1f*10**15 m/s**2\" %(ay/10**15))\n",
+    "#The negative sign tells us that the direction of this acceleration is downward "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.6 , Page number 28"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "velocity with which electron beam will travel= 2.65*10**7 m/s\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ey=3*10**4 #electric field in y-axis in N/C\n",
+    "V=2000 #potential in V\n",
+    "e=1.602*10**-19 #electronic charge in eV\n",
+    "m=9.1*10**-31 #mass of electron in kg\n",
+    "\n",
+    "#Calculations\n",
+    "u=math.sqrt((2*V*e)/m)\n",
+    "\n",
+    "#Result\n",
+    "print(\"velocity with which electron beam will travel= %.2f*10**7 m/s\" %(u/10**7))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 1.7 , Page number 28"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Time taken= 3.8 s\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "l=5 #length to be covered in cm\n",
+    "up=26.5*10**8 #in cm/s\n",
+    "\n",
+    "#Calculations\n",
+    "t=(2*l/up)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Time taken= %1.1f s\" %(t/10**-9))\n",
+    "#The answers vary due to round off error"
+   ]
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter2_RLHLaga.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter2_RLHLaga.ipynb
new file mode 100644
index 00000000..63a5a06a
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter2_RLHLaga.ipynb
@@ -0,0 +1,382 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 2 : Growth and Crystal properties of Semiconductor "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.1 , Page number 42"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Each corner sphere of the bcc unit cell is shared with eigth neighbouring  cells.Thus each cell contains one eigth of a sphere at all the eigth corners.Each unit cell also contains one central sphere\n",
+      "bcc unit cell volume filled with hard sphere= 68 %\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "print(\"Each corner sphere of the bcc unit cell is shared with eigth neighbouring  cells.Thus each cell contains one eigth of a sphere at all the eigth corners.Each unit cell also contains one central sphere\")\n",
+    "S=2 #Sphere per unit cell\n",
+    "\n",
+    "#Calculations\n",
+    "f=S*math.pi*math.sqrt(3)/16 #maximum fraction of a unit cell\n",
+    "\n",
+    "#Result\n",
+    "print(\"bcc unit cell volume filled with hard sphere= %i %%\" %round(f*100))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.2 , Page number 43"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "The plane depicted in the figure is denoted by (6,3,2)\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "# r = p*a + q*b + s*c\n",
+    "p=1\n",
+    "q=2\n",
+    "s=3\n",
+    "LCM=6\n",
+    "\n",
+    "#Calculations\n",
+    "rx=1/p*LCM #reciprocals\n",
+    "ry=1/q*LCM\n",
+    "rz=1/s*LCM\n",
+    "\n",
+    "#Result\n",
+    "\n",
+    "print(\"The plane depicted in the figure is denoted by (%i,%i,%i)\" %(rx,ry,rz))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.3 , Page number 43"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Density of Si= 2.33 g/cm**3\n",
+      "\n",
+      "Density of GaAs= 5.33 g/cm**3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "#Atomic weigths\n",
+    "Si=28.1 \n",
+    "Ga=69.7\n",
+    "As=74.9\n",
+    "Na=6.02*10**23 # Avagadro Number in mol**-1\n",
+    "\n",
+    "#(a)Si\n",
+    "a=5.43*10**-8 #in cm\n",
+    "n=8 #no. of atoms/cell\n",
+    "\n",
+    "#(b)GaAs\n",
+    "a1=5.65*10**-8 #in cm                \n",
+    "\n",
+    "#Calculations\n",
+    "N=8/a**3 #Atomic Concentration in atoms/cc\n",
+    "N1=4/a1**3 #Atomic Concentration in atoms/cc\n",
+    "Density=(N*Si)/(Na)\n",
+    "Density1=(N1*(Ga+As))/(Na)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Density of Si= %1.2f g/cm**3\\n\" %Density)#answer vary due to round-off error\n",
+    "print(\"Density of GaAs= %1.2f g/cm**3\" %Density1)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.4 , Page number 44"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "n(111)= 2.3*10**18 atoms/m**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "a=5*10**-10 #lattice constatnt in m\n",
+    "\n",
+    "#Calculations\n",
+    "n111=1/(a**2*math.sqrt(3))\n",
+    "\n",
+    "#Result\n",
+    "print(\"n(111)= %.1f*10**18 atoms/m**2\" %(n111/10**18))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.5 , Page number 56"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(a)Cl= 1.43*10**17 cm**-3\n",
+      "\n",
+      "(b)Wt of P= 12.63*10**-3 g\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Cs=5*10**16 #impurity concentration in solid in atoms/cm**3\n",
+    "ks=0.35 #segregation coefficient \n",
+    "d=2.33 #density of Si in g/cm**3\n",
+    "Na=6.02*10**23 # Avagadro Number in mol**-1\n",
+    "Si=31 #weight of Si\n",
+    "loadSi=4000 #initial load in gm\n",
+    "\n",
+    "#Calculations\n",
+    "Cl=Cs/ks #impurity concentration in liquid\n",
+    "V=loadSi/d #volume of the melt in cm**3\n",
+    "Nummber_of_atoms=Cl*V #in atoms\n",
+    "Wt=(Cl*V*Si)/(Na)\n",
+    "\n",
+    "#Result\n",
+    "print(\"(a)Cl= %1.2f*10**17 cm**-3\\n\" %(Cl/10**17))\n",
+    "print(\"(b)Wt of P= %.2f*10**-3 g\" %(Wt/10**-3)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.7 , Page number 59"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Miller indices of plane are (20,15,12)\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "# r = p*a + q*b + s*c\n",
+    "x=3 #intercept on x axis\n",
+    "y=4 #intercept on y axis\n",
+    "z=5 #intercept on z zxis\n",
+    "LCM=60 \n",
+    "\n",
+    "#Calculations\n",
+    "rx=1/x*LCM #reciprocal\n",
+    "ry=1/y*LCM\n",
+    "rz=1/z*LCM\n",
+    "\n",
+    "#Result\n",
+    "print(\"Miller indices of plane are (%i,%i,%i)\" %(rx,ry,rz))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.9 , Page number 60"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(a)no. of atoms in each cell= 8\n",
+      "\n",
+      "(b)Density of atoms in silicon= 5*10**22 atoms cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "a=8 #number of atoms shared by 8 cells\n",
+    "b=6 #number of atoms shared by 2 cells\n",
+    "c=4 #number of atoms shared by a single cell\n",
+    "L=5.43*10**-8 #Lattice constant in cm\n",
+    "\n",
+    "#Calculations\n",
+    "N=(a/8)+(b/2)+c #no. of atoms in each cell\n",
+    "Volume=L**3\n",
+    "Density=8/Volume\n",
+    "\n",
+    "#Result\n",
+    "print(\"(a)no. of atoms in each cell= %i\\n\" %N)\n",
+    "print(\"(b)Density of atoms in silicon= %i*10**22 atoms cm**-3\" %round(Density/10**22))\n",
+    "#The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 2.10, Page number 60"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Density per unit volume= 2.33 g cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=6.02*10**23 # Avagadro Number in mol**-1\n",
+    "AtWt=28.09 #in g/mole\n",
+    "Density=5*10**22 #in atoms/cm**-3\n",
+    "\n",
+    "#Calculations\n",
+    "DensityPerUnitVolume=(Density*AtWt)/(Na)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Density per unit volume= %1.2f g cm**-3\" %DensityPerUnitVolume)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter3_PZ90WhS.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter3_PZ90WhS.ipynb
new file mode 100644
index 00000000..901966f7
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter3_PZ90WhS.ipynb
@@ -0,0 +1,606 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 3 : Energy Bands and Charge Carriers in Semiconductors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.1 , Page number 75"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 31,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Increase in kinetic energy of electron= 5.7*10**-8 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "v=5*10**5 #velocity of electron in cm/s\n",
+    "m=9.11*10**-31 #mass of electron in kg\n",
+    "const=1.6*10**-19 #in eV\n",
+    "\n",
+    "#Calculations\n",
+    "delv=0.02 #change in speed in cm/s\n",
+    "delE=(m*v*delv)/const\n",
+    "\n",
+    "#Result\n",
+    "print(\"Increase in kinetic energy of electron= %1.1f*10**-8 eV\" %(delE/10**-8))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.2 , Page number "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 32,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Energy required to excite the donor electron= 8.34*10**-22 J\n",
+      "\n",
+      "Energy required to excite the donor electron= 0.0052 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "epsilon_r=13.2 \n",
+    "m0=9.11*10**-31 #in kg\n",
+    "q=1.6*10**-19 #in eV\n",
+    "epsilon_0=8.85*10**-12 #in F/m\n",
+    "h=6.63*10**-34 #planck's constant in J/s \n",
+    "\n",
+    "#Calculations\n",
+    "mn=0.067*m0 #in kg\n",
+    "E=((mn*q**4)/(8*(epsilon_0*epsilon_r)**2*h**2))\n",
+    "E1=E/q\n",
+    " \n",
+    "#Result\n",
+    "print(\"Energy required to excite the donor electron= %.2f*10**-22 J\\n\" %(E/10**-22))\n",
+    "print(\"Energy required to excite the donor electron= %.4f eV\" %E1)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.3 , Page number 110"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Density of states effective mass of electrons in silicon= 1.1 m0\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ml=0.98#*m0\n",
+    "mt=0.19#*m0\n",
+    "#rest mass m0 = 9.1*10**-31 kg            \n",
+    "\n",
+    "#Calculations\n",
+    "mn=6**(2/3)*(ml*mt**2)**(1/3)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Density of states effective mass of electrons in silicon= %1.1f m0\" %mn)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.4 , Page number 110"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 34,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Ef-Ei= 0.347 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n0=10**16 #doping atoms of P in atoms/cm**3\n",
+    "ni=1.5*10**10 #in cm**-3 \n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "p0=(ni**2)/n0 #in cm**-3\n",
+    "x=(n0/ni) \n",
+    "delE=Const*math.log(x) #difference between energy bands Ef-Ei\n",
+    "\n",
+    "#Result\n",
+    "print(\"Ef-Ei= %.3f eV\" %delE)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.5 , Page number 111"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1/mnc*= 0.26 m0\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ml=0.98#*m0\n",
+    "mt=0.19#*m0\n",
+    "#rest mass m0 = 9.1*10**-31 kg\n",
+    "\n",
+    "#Calculations\n",
+    "mnc=0.33*(1/ml+2/mt)\n",
+    "\n",
+    "#Result\n",
+    "print(\"1/mnc*= %1.2f m0\" %(1/mnc))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.6 , Page number 111"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Resistivity of the sample p= 16.03 ohm-cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=10**14 #in cm**-3\n",
+    "myu_n=3900 #in cm**2/V\n",
+    "e=1.6*10**-19 #in J\n",
+    "\n",
+    "#Calculations\n",
+    "p=1/(Nd*e*myu_n)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Resistivity of the sample p= %.2f ohm-cm\" %p)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.7 , Page number 111"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 37,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Resistivity= 0.156 ohm-cm\n",
+      "\n",
+      "Hall coefficient= -125 cm**3/c\n",
+      "\n",
+      "Hall Voltage= -62.5*10**-5 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n0=5*10**16 #doping level of Si with As in cm**-3\n",
+    "myu_n=800 #in cm**2/Vs\n",
+    "Ix=2*10**-3 #in A\n",
+    "Bz=5*10**-5 #in A\n",
+    "d=2*10**-2 #in cm\n",
+    "e=1.6*10**-19 #in J\n",
+    "\n",
+    "#Calculations\n",
+    "p=1/(e*myu_n*n0) \n",
+    "RH=-1/(e*n0) \n",
+    "VH=(Ix*Bz*RH)/(d)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Resistivity= %0.3f ohm-cm\\n\" %p)\n",
+    "print(\"Hall coefficient= %i cm**3/c\\n\" %RH)\n",
+    "print(\"Hall Voltage= %.1f*10**-5 V\" %(VH/10**-5))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.9 , Page number 111"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 38,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Density of majority carriers(holes)= 9.2*10**17 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Boron_impurity=10**18 #in cm**-3\n",
+    "Phosphorus_impurity=10**16 #in cm**-3\n",
+    "\n",
+    "#Calculations\n",
+    "Density=Boron_impurity-(8*Phosphorus_impurity)\n",
+    "\n",
+    "print(\"Density of majority carriers(holes)= %1.1f*10**17 cm**-3\" %(Density/10**17))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.10 , Page number 115"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 39,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Drift velocity of remaining hole group= -11.3*10**8 cm s**-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "J=14.14*10**-14 #current density in A/cm**2\n",
+    "v1=3*10**7 #hole group drift velocities in cm/s\n",
+    "v2=5*10**8 #in cm/s\n",
+    "v3=6*10**8 #in cm/s\n",
+    "q=1.6*10**-19 #in C\n",
+    "n=1000 #number of holes\n",
+    "\n",
+    "#Calculations\n",
+    "x=((J/(n*q))-v1-v2-v3)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Drift velocity of remaining hole group= %.1f*10**8 cm s**-1\" %(x/10**8))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.11 , Page number 115"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 40,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)minimum frequency= 3.454*10**14 Hz\n",
+      "\n",
+      "b)wavelength= 8.7*10**-7 m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=1.43 #in eV\n",
+    "h=4.14*10**-15 #plancks constant in e*V*s\n",
+    "c=3*10**8 #in m/s\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "v=E/h\n",
+    "\n",
+    "#b)\n",
+    "lamda=c/v\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)minimum frequency= %.3f*10**14 Hz\\n\" %(v/10**14))\n",
+    "print(\"b)wavelength= %.1f*10**-7 m\" %(lamda/10**-7)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.12 , Page number 116"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)Limiting electric field= 100 V/cm\n",
+      "\n",
+      "b)Length of resistor= 5.0*10**-2 cm\n",
+      "\n",
+      "c)Area of cross-section= 1.0*10**-5 cm**2\n",
+      "\n",
+      "d)Acceptor doping concentration= 5.00*10**15 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "R=10*10**3 #Resistance in ohm\n",
+    "V=5 #Voltage in V\n",
+    "J=50 #current density in A/cm**2\n",
+    "E=100 #in V/cm\n",
+    "q=1.6*10**10 #in eV\n",
+    "myu_p=410 #in cm**2/V*s\n",
+    "Nd=5*10**15 #in cm**-3\n",
+    "\n",
+    "#Calculations\n",
+    "I=V/R #ohms law in mA\n",
+    "A=I/J #Area in cm**2\n",
+    "L=V/E \n",
+    "rho=(R*A)/L\n",
+    "sigma=1/rho #in ohm**-1 cm**-1\n",
+    "Na=(sigma/(myu_p*q))+Nd\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)Limiting electric field= %i V/cm\\n\" %E)\n",
+    "print(\"b)Length of resistor= %.1f*10**-2 cm\\n\" %(L/10**-2))\n",
+    "print(\"c)Area of cross-section= %.1f*10**-5 cm**2\\n\" %(A/10**-5))\n",
+    "print(\"d)Acceptor doping concentration= %.2f*10**15 cm**-3\" %(Na/10**15)) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.13 , Page number 117"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)Doping value= 1.109*10**16 cm**-3\n",
+      "\n",
+      "c)resistivity of the doped pieces of silicon= 0.4025 ohm-cm\n",
+      "\n",
+      "c)resistivity of the undoped pieces of silicon= 2.2*10**5 ohm-cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E_fi=0.35 #in eV\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "q=1.6*10**-19 #in eV\n",
+    "myu_n=1400 #in cm**2/Vs\n",
+    "myu_p=500 #in cm**2/Vs\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "n0=ni*math.exp((E_fi)/Const)\n",
+    "\n",
+    "#c)\n",
+    "#doped substrate\n",
+    "sigma=q*(myu_n*n0) #in ohm**-1 cm**-1\n",
+    "rho=1/sigma\n",
+    "\n",
+    "#undoped substrate\n",
+    "sigma1=q*(ni*(myu_n+myu_p))\n",
+    "rho1=1/sigma1\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)Doping value= %1.3f*10**16 cm**-3\\n\" %(n0/10**16))\n",
+    "print(\"c)resistivity of the doped pieces of silicon= %.4f ohm-cm\\n\" %rho)\n",
+    "print(\"c)resistivity of the undoped pieces of silicon= %.1f*10**5 ohm-cm\" %(rho1/10**5)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 3.14 , Page number 119"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 43,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "concentration of doping= 1.726*10**20 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Ex=0.6 #position of energy level in eV\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "n0=ni*math.exp(Ex/Const)\n",
+    "\n",
+    "#Result\n",
+    "print(\"concentration of doping= %.3f*10**20 cm**-3\" %(n0/10**20)) #The answers vary due to round off error"
+   ]
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.12"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter4_WU1E9Hg.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter4_WU1E9Hg.ipynb
new file mode 100644
index 00000000..cf309081
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter4_WU1E9Hg.ipynb
@@ -0,0 +1,491 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 4 : Excess Carriers in Semiconductors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.1 , Page number 135"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "excess electron concentration= 8.19*10**15 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "del_n0=10**16 #concentration of electrons in cm**-3\n",
+    "tau_n0=5 #excess carrier lifetime in micro-s\n",
+    "t=1 #time in micro-s\n",
+    "\n",
+    "#Calculations\n",
+    "del_nt=del_n0*math.exp(-t/tau_n0)\n",
+    "\n",
+    "#Result\n",
+    "print(\"excess electron concentration= %.2f*10**15 cm**-3\" %(del_nt/10**15))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.2 , Page number 135"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Recombination rate= 0.74*10**21 cm**-3 s**-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "del_n0=10**16 #concentration of electrons in cm**-3\n",
+    "tau_n0=5 #excess carrier lifetime in s\n",
+    "tau_n01=5*10**-6 #excess carrier lifetime in micro-s\n",
+    "t=5 #in micro-s\n",
+    "\n",
+    "#Calculations\n",
+    "del_nt=del_n0*math.exp(-t/tau_n0) #in cm**-3\n",
+    "Rn1=del_nt/tau_n01\n",
+    "\n",
+    "#Result\n",
+    "print(\"Recombination rate= %.2f*10**21 cm**-3 s**-1\" %(Rn1/10**21))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.3 , Page number 136"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Recombination rate= 9.17*10**19 cm**-3 s**-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=10**15 #dopant concentration in cm**-3\n",
+    "Na=0 #in cm**-3\n",
+    "tau_p0=10*10**-7 #in s\n",
+    "tau_n0=10*10**-7 #in s\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "deln=10**14 #in cm**-3\n",
+    "delp=10**14 #in cm**-3\n",
+    "nt=1.5*10**15 #in cm**-3\n",
+    "pt=1.5*10**15 #in cm**-3\n",
+    "               \n",
+    "#Calculations\n",
+    "n0=Nd #in cm**-3\n",
+    "p0=ni**2/Nd #in cm**-3\n",
+    "n=n0+deln #in cm**-3\n",
+    "p=p0+delp #in cm**-3\n",
+    "R=((n*p)-ni**2)/(tau_n0*(n+p))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Recombination rate= %1.2f*10**19 cm**-3 s**-1\" %(R/10**19))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.4 , Page number 146"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1)\n",
+      "position of the Fermi level at thermal equilibrium= 0.3412 eV\n",
+      "\n",
+      "2)\n",
+      "quasi-Fermi level for electrons in non-equilibrium= 0.3414 eV\n",
+      "\n",
+      "3)\n",
+      "quasi-Fermi level for holes in non-equilibrium= 0.2214 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n0=5*10**15 #carrier concentration in cm**-3\n",
+    "ni=10**10 #in cm**-3\n",
+    "p0=2*10**4 #in cm**-3\n",
+    "deln=5*10**13 #excess carriers in semiconductor in cm**-3\n",
+    "delp=5*10**13 #in cm**-3\n",
+    "Const=0.026 #constant value for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "delE1=Const*math.log(n0/ni) \n",
+    "delE2=Const*math.log((n0+deln)/ni)\n",
+    "delE3=Const*math.log((p0+delp)/ni)\n",
+    "\n",
+    "#Result\n",
+    "print(\"1)\\nposition of the Fermi level at thermal equilibrium= %0.4f eV\\n\" %delE1)\n",
+    "print(\"2)\\nquasi-Fermi level for electrons in non-equilibrium= %0.4f eV\\n\" %delE2)\n",
+    "print(\"3)\\nquasi-Fermi level for holes in non-equilibrium= %0.4f eV\" %delE3)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.6 , Page number 147"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1)\n",
+      "Hole mobility= 2000 cm**2/Vs\n",
+      "\n",
+      "2)\n",
+      "Diffusion coefficient= 52.22 cm**2/s\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "l=1.8 #distance between plates in cm\n",
+    "E=3/2 #in V\n",
+    "t=0.6*10**-3 #time taken by the pulse in s \n",
+    "del_t=236*10**-6 #pulse width in s\n",
+    "\n",
+    "#Calculations\n",
+    "vd=l/t #in cm/s\n",
+    "myu_p=vd/E\n",
+    "Dp=(del_t*l)**2/(16*t**3)\n",
+    "\n",
+    "#Result\n",
+    "print(\"1)\\nHole mobility= %i cm**2/Vs\\n\" %myu_p)\n",
+    "print(\"2)\\nDiffusion coefficient= %2.2f cm**2/s\" %Dp)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.7 , Page number 149"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 22,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "\n",
+      "photo generation rate= 8*10**20 EHPs/cm**3s\n",
+      "\n",
+      "b)\n",
+      "\n",
+      "resistivity before illumination= 5.21 ohm-cm\n",
+      "\n",
+      "resistvity after illumination= 3.397 ohm-cm\n",
+      "\n",
+      "percent of conductivity= 8.70 percent\n",
+      "\n",
+      "c)\n",
+      "\n",
+      "quasi Fermi level due to electron=Efi+0.296 eV\n",
+      "\n",
+      "quasi Fermi level due to holes=Efi-0.264 eV\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "delp=4*10**14 #excess EHP in cm**-3\n",
+    "deln=4*10**14 #excess EHP in cm**-3\n",
+    "n0=10**15 #donor atoms in cm**-3\n",
+    "p0=0 #in cm**-3\n",
+    "t=0.5*10**-6 #hole-lifetime in s\n",
+    "myu_n=1200 #mobility of electron in cm**2/V*s\n",
+    "myu_p=400 #mobility of hole in cm**2/V*s\n",
+    "q=1.6*10**-19 #electron charge in eV\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "gop=delp/t\n",
+    "\n",
+    "#b)\n",
+    "rho_0=(q*n0*myu_n)**-1 #Before illumination\n",
+    "n=n0+deln #in cm**-3\n",
+    "p=p0+delp #in cm**-3\n",
+    "rho=1/(q*((myu_n*n)+(myu_p*p)))#conductivity\n",
+    "rho1=q*myu_p*delp #in mho/cm\n",
+    "Pcond=(rho*rho1)*100\n",
+    "\n",
+    "#c)\n",
+    "delE_e=Const*math.log(n/ni)\n",
+    "delE_h=Const*math.log(p/ni)\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\n\")\n",
+    "print(\"photo generation rate= %i*10**20 EHPs/cm**3s\\n\" %(gop/10**20))\n",
+    "print(\"b)\\n\")\n",
+    "print(\"resistivity before illumination= %1.2f ohm-cm\\n\" %rho_0)\n",
+    "print(\"resistvity after illumination= %1.3f ohm-cm\\n\" %rho)\n",
+    "print(\"percent of conductivity= %1.2f percent\\n\" %Pcond) #The answers vary due to round off error\n",
+    "print(\"c)\\n\")\n",
+    "print(\"quasi Fermi level due to electron=Efi+%0.3f eV\\n\" %delE_e)\n",
+    "print(\"quasi Fermi level due to holes=Efi-%0.3f eV\\n\" %delE_h)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.8 , Page number 151"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "\n",
+      "lifetime of both type of carriers= 1 micro-s\n",
+      "\n",
+      "b)\n",
+      "\n",
+      "excess carrier concentration= 1*10**15 cm**-3\n",
+      "\n",
+      "c)\n",
+      "\n",
+      "Induced change in current= 0.064 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "n0=10**16 #donor atoms in cm**-3\n",
+    "q=1.6*10**-19 #electron charge in J\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Nd=10**16 #Donors added to silicon to make it n-type) in cm**-3\n",
+    "GT=2.25*10**10 #Thermal generation rate of carriers under equilibrium cm**-3/s\n",
+    "gop=10**21 #in cm**-3/s\n",
+    "tau_n=10**-6 #in s\n",
+    "tau_t=2.5*10**-3 #transit time in s\n",
+    "V=1 #in V\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "alpha_r=GT/ni**2\n",
+    "tau_p=(alpha_r*n0)**-1\n",
+    " \n",
+    "#b)\n",
+    "delp=gop*tau_n\n",
+    "\n",
+    "#c)\n",
+    "delI=(q*V*gop*tau_n)/tau_t\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\n\")\n",
+    "print(\"lifetime of both type of carriers= %i micro-s\\n\" %(tau_p/10**-6))\n",
+    "print(\"b)\\n\")\n",
+    "print(\"excess carrier concentration= %i*10**15 cm**-3\\n\" %(delp/10**15))\n",
+    "print(\"c)\\n\")\n",
+    "print(\"Induced change in current= %.3f A\" %delI)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 4.9 , Page number 151"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "\n",
+      "Current density for 1000V potential= 8.48*10**5 A/cm**2\n",
+      "\n",
+      "b)\n",
+      "\n",
+      "Doping concentration= 7.1*10**11 cm**-3\n",
+      "\n",
+      "c)\n",
+      "\n",
+      "Energy gap= 0.3280 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E1000=8.48*10**5 #Current density for 1000 V in A/cm**2\n",
+    "delE=0.1 #in eV\n",
+    "q=1.6*10**-19 #electron charge in eV\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Nd=10**16 #Donors added to silicon to make it n-type) in cm**-3\n",
+    "gop=10**19 #in cm**-3/s\n",
+    "tau=10**-5 #in s\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "E10000=E1000\n",
+    "\n",
+    "#b)\n",
+    "n0=ni*math.exp(delE/Const)\n",
+    "\n",
+    "#c)\n",
+    "deln=gop*tau #in cm**-3\n",
+    "n=n0 #in cm**-3\n",
+    "p=deln #in cm**-3s\n",
+    "delE_np=Const*math.log((n*p)/ni**2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\n\")\n",
+    "print(\"Current density for 1000V potential= %1.2f*10**5 A/cm**2\\n\" %(E10000/10**5))\n",
+    "print(\"b)\\n\")\n",
+    "print(\"Doping concentration= %1.1f*10**11 cm**-3\\n\" %(n0/10**11)) #The answer provided in the textbook is wrong\"\n",
+    "print(\"c)\\n\")\n",
+    "print(\"Energy gap= %0.4f eV\" %delE_np) #The answer provided in the textbook is wrong\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter5_DR2oZl3.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter5_DR2oZl3.ipynb
new file mode 100644
index 00000000..c69c6d26
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter5_DR2oZl3.ipynb
@@ -0,0 +1,499 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 5 : P - N Junction"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.1 , Page number 180"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "rootD = 0.18 micro-m/h**-2\n",
+      "\n",
+      "Temperature at diffusion should be carried out= 1100 Celsius\n",
+      "The temperature value was choosen by determing the value of T against root(D) in the figure of Diffusivity of acceptor impurities in silicon versus T\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "rho=10 #resistivity in ohm-cm\n",
+    "myu_n=1300 #electron mobility in cm**2/V*s\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Cs=5*10**18 #constant surface concentartion in cm**-3\n",
+    "t=1 #in hour\n",
+    "x=1 #depth in micro-m\n",
+    "\n",
+    "#Calculations\n",
+    "sigma=1/rho #in (ohm-cm)**-1\n",
+    "n=sigma/(myu_n*e) #in cm**-3\n",
+    "n_Cs=n/Cs \n",
+    "erfc1_y=n_Cs #error function\n",
+    "y=2.75 #reference page 181 from fig 5.1.1. value obtained by plotting erfc1_y (Complementary error function) as a function of y\n",
+    "rootD=x/(2*y*math.sqrt(t))\n",
+    "T=1100 #reference page 168 from fig 5.10(b)\n",
+    "\n",
+    "#Result\n",
+    "print(\"rootD = %.2f micro-m/h**-2\\n\" %rootD)\n",
+    "print(\"Temperature at diffusion should be carried out= %i Celsius\" %T)\n",
+    "print(\"The temperature value was choosen by determing the value of T against root(D) in the figure of Diffusivity of acceptor impurities in silicon versus T\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.2 , Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "built-in potential= 0.841 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=5*10**18 #doping densities in cm**-3\n",
+    "Nd=5*10**15 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Const=0.026#constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Vbi=Const*math.log((Na*Nd)/ni**2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"built-in potential= %0.3f V\" %Vbi) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.3 , Page number 182"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Total space-charge width= 0.466 micro-m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=5*10**18 #doping densities in cm**-3\n",
+    "Nd=5*10**15 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3 \n",
+    "epsilon_s=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Vbi=0.838 #built-in potential in V\n",
+    "e=1.6*10**-19 #in J                \n",
+    "\n",
+    "#Calculations\n",
+    "W=((2*epsilon_s*epsilon_0*Vbi*(Na+Nd))/(e*Na*Nd))**0.5\n",
+    "\n",
+    "#Result\n",
+    "print(\"Total space-charge width= %0.3f micro-m\" %(W/10**-4))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.4 , Page number 201"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Total space-charge width= 1.12 micro-m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=5*10**18 #doping densities in cm**-3\n",
+    "Nd=5*10**15 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "VR=4 #voltage in V\n",
+    "epsilon_s=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Vbi=0.838 #built-in potential in V\n",
+    "e=1.6*10**-19 #in J\n",
+    "\n",
+    "#Calculations\n",
+    "W=((2*epsilon_s*epsilon_0*(Vbi+VR)*(Na+Nd))/(e*Na*Nd))**0.5\n",
+    "\n",
+    "#Result\n",
+    "print(\"Total space-charge width= %1.2f micro-m\" %(W/10**-4))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.5 , Page number 143"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Junction Capacitance= 1*10**-8 F/cm**2\n",
+      "\n",
+      "Depletion Capacitance= 5 pF\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=5*10**18 #doping densities in cm**-3\n",
+    "Nd=5*10**15 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "VR=3 #voltage in V\n",
+    "epsilon_s=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Vbi=0.838 #built-in potential in V\n",
+    "e=1.6*10**-19 #in J\n",
+    "A=5*10**-4 #Area in cm**2\n",
+    "\n",
+    "#Calculations\n",
+    "Cdep=((e*epsilon_s*epsilon_0*Na*Nd)/(2*(Vbi+VR)*(Na+Nd)))**0.5 #junction capacitance \n",
+    "Cdep1=Cdep*A\n",
+    "\n",
+    "#Result\n",
+    "print(\"Junction Capacitance= %i*10**-8 F/cm**2\\n\" %(Cdep/10**-8))\n",
+    "print(\"Depletion Capacitance= %i pF\" %(Cdep1/10**-12))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.7 , Page number 205"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Breakdown voltage= 13.87 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=10**17 #in cm**-3\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Emax=5*10**5 #peak electric field in V/cm\n",
+    "e=1.6*10**-19 #in J\n",
+    "epsilon_si=88.76*10**-14 #in F/cm\n",
+    "\n",
+    "#Calculations\n",
+    "E=(Emax*Emax*epsilon_si)/(e*Na)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Breakdown voltage= %2.2f V\" %E) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.8 , Page number 206"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      " As 18.24 micro-m is less than the given length of the n-region i.e 22 micro-m, device will only have avalanche breakdown\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=10**19 #doping densities in cm**-3\n",
+    "Nd=10**15 #in cm**-3\n",
+    "epsilon_s=88.76*10**-14 #in F/cm\n",
+    "e=1.6*10**-19 #in J\n",
+    "Vbi=300 #breakdown voltage in V\n",
+    "\n",
+    "#Calculations\n",
+    "xn=((2*epsilon_s*Na*Vbi)/(e*Nd*(Na+Nd)))**0.5\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\")\n",
+    "print(\" As %.2f micro-m is less than the given length of the n-region i.e 22 micro-m, device will only have avalanche breakdown\" %(xn/10**-4))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.9 , Page number 207"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "\n",
+      "Total concentration of holes= 5.45*10**11 cm**-3\n",
+      "\n",
+      "b)\n",
+      "\n",
+      "Additional voltage required= 0.9051 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=10**15 #doping densities in cm**-3\n",
+    "Nd=10**17 #in cm**-3\n",
+    "V=0.5 #in V\n",
+    "e=1.6*10**-19 #in J\n",
+    "nn0=10**17 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Si_bandgap=1.1 #bandgap of silicon in eV\n",
+    "Const=0.0259 #constant value for kT/e in J\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "pn0=ni**2/nn0 #in cm**-3\n",
+    "pn=pn0*math.exp((V)/Const) \n",
+    "\n",
+    "#b)\n",
+    "\n",
+    "Vbi=0.6949 #breakdown voltage in V\n",
+    "Vp=Vbi-V #potential already present in V\n",
+    "Vz=Si_bandgap-Vp #Zener breakdown voltage in V\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\n\")\n",
+    "print(\"Total concentration of holes= %.2f*10**11 cm**-3\\n\" %(pn/10**11)) \n",
+    "print(\"b)\\n\")\n",
+    "print(\"Additional voltage required= %.4f V\" %Vz)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.10 , Page number 208"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Donor Concentration= 3.447*10**18 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Cj=12*10**-12 #Capacitance in F/cm**2\n",
+    "A=10**-4 #junction Area in A/cm**2\n",
+    "Vr=20 #in V\n",
+    "e=1.6*10**-19 #in J\n",
+    "epsilon_r=11.8 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "\n",
+    "#Calculations\n",
+    "Nd=((2*Cj)/A)**2*(Vr/(2*epsilon_r*epsilon_0*e))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Donor Concentration= %1.3f*10**18 cm**-3\" %(Nd/10**18))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 5.11 , Page number 209"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Depletion capacitance per unit area= 1.804 nF/cm**2\n",
+      "\n",
+      "Width of depletion region= 5.74*10**-4 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Na=4.22*10**14 #doping densities in cm**-3\n",
+    "Nd=4.22*10**16 #in cm**3\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Vbi=0.65 #breakdown voltage in V\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "epsilon_si=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "V=10 #applied voltage in V\n",
+    "Const=0.0259 #value for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Nd=math.sqrt((math.exp(Vbi/Const)*ni**2)/100)\n",
+    "Na=100*Nd\n",
+    "W=(((2*epsilon_0*epsilon_si*(Vbi+V))*(Na+Nd))/(e*Na*Nd))**0.5\n",
+    "Cj=(epsilon_0*epsilon_si)/W\n",
+    "\n",
+    "#Result\n",
+    "print(\"Depletion capacitance per unit area= %1.3f nF/cm**2\\n\" %(Cj/10**-9)) #The answers vary due to round off error\n",
+    "print(\"Width of depletion region= %1.2f*10**-4 cm\" %(W/10**-4)) #The answers vary due to round off error"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter6_qpsBdAt.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter6_qpsBdAt.ipynb
new file mode 100644
index 00000000..d8624900
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter6_qpsBdAt.ipynb
@@ -0,0 +1,483 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 6 : P - N Junction Current"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.1 , Page number 226"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "minority carrier concentration= 6.92*10**12 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Nd=5*10**16 #doping density in cm**-3\n",
+    "V=0.55 #in V\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Pn0=ni**2/Nd #in cm**-3\n",
+    "Pn=Pn0*math.exp(V/Const)\n",
+    "\n",
+    "#Result\n",
+    "print(\"minority carrier concentration= %1.2f*10**12 cm**-3\" %(Pn/10**12))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.2 , Page number 226"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Reverse saturation current density= 4.38*10**-11 A/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "Na=10**16 #doping density in cm**-3\n",
+    "Nd=5*10**16 #in cm**-3\n",
+    "Dn=25 #in cm**2/s\n",
+    "Dp=10 #in cm**2/s\n",
+    "tau_p0=4*10**-7 #in s\n",
+    "tau_n0=2*10**-7 #in s\n",
+    "\n",
+    "#Calculations\n",
+    "Js=e*ni**2*((1/Na)*math.sqrt(Dn/tau_n0)+(1/Nd)*math.sqrt(Dp/tau_p0))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Reverse saturation current density= %1.2f*10**-11 A/cm**2\" %(Js/10**-11)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.3 , Page number 227"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1)\n",
+      "Reverse bias stauration current density= 0.620*10**-6 A/m**2\n",
+      "\n",
+      "2)\n",
+      "Ratio of hole to electron current= 37.69 \n",
+      "\n",
+      "3)\n",
+      "Total current density= 2.98 A/m**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "sigma_p=1000 #conductivity of p-junction in ohm**-1*m**-1\n",
+    "sigma_n=20 #conductivity of n-junction in ohm**-1*m**-1\n",
+    "myu_p=0.05 #in m**2/V*s\n",
+    "myu_n=0.13 #in m**2/V*s\n",
+    "K=8.61*10**-5 #Boltzmann constant in eV/K\n",
+    "T=300 #in K\n",
+    "V=0.4 #forward bias voltage in V\n",
+    "e=1.602*10**-19 #in J\n",
+    "ni=1.5*10**16 #in m**-3\n",
+    "tau_n=10**-6 #minority carrier lifetime in s\n",
+    "tau_p=5*10**-6 #in s\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "hole_current=0.603*10**-6 #in A\n",
+    "electron_current=0.016*10**-6 #in A                 \n",
+    "\n",
+    "#Calculations\n",
+    "pp0=sigma_p/(e*myu_p) #majority carrier densities in m**-3\n",
+    "nn0=sigma_n/(e*myu_n) #in m**-3\n",
+    "np0=ni**2/pp0 #minority carrier densities in m**-3\n",
+    "pn0=ni**2/nn0 #in m**-3\n",
+    "Dn=myu_n*K*T #in m**2/s\n",
+    "Dp=myu_p*K*T #in m**2/s\n",
+    "Ln=math.sqrt(Dn*tau_n) #in m\n",
+    "Lp=math.sqrt(Dp*tau_p) #in m\n",
+    "Js=(((e*np0*Ln)/tau_n)+((e*pn0*Lp)/tau_p))\n",
+    "Ratio=(hole_current)/(electron_current)\n",
+    "J=Js*(math.exp(V/Const)-1)\n",
+    "\n",
+    "#Result\n",
+    "print(\"1)\\nReverse bias stauration current density= %0.3f*10**-6 A/m**2\\n\" %(Js/10**-6)) #The answers vary due to round off error\n",
+    "print(\"2)\\nRatio of hole to electron current= %2.2f \\n\" %Ratio)\n",
+    "print(\"3)\\nTotal current density= %2.2f A/m**2\" %J) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.4 , Page number 242"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Diffusion Capacitance= 4*10**-9 F\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Ip0=0.5*10**-3 #in A\n",
+    "tau_p0=5*10**-7 #in s\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Cd0=(1/(2*Const))*tau_p0*Ip0\n",
+    "\n",
+    "#Result\n",
+    "print(\"Diffusion Capacitance= %i*10**-9 F\" %math.floor(Cd0/10**-9))\n",
+    "#The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.5 , Page number 243"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "reverse-bias generation current density= 3.15*10**-7 A/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "epsilon_si=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "e=1.6*10**-19 #in J\n",
+    "Na=10**16 #in cm**-3\n",
+    "Nd=5*10**16 #in cm**-3\n",
+    "tau_p0=4*10**-7 #in s\n",
+    "tau_n0=2*10**-7 #in s\n",
+    "\n",
+    "#Calculations\n",
+    "W=(((2*epsilon_si*epsilon_0)*(Na+Nd)*4)/(e*Na*Nd))**0.5 #in micro-m\n",
+    "tau_m=(tau_p0+tau_n0)/2 #in s\n",
+    "Jgen=(e*ni*W)/(2*tau_m) \n",
+    "\n",
+    "#Result\n",
+    "print(\"reverse-bias generation current density= %1.2f*10**-7 A/cm**2\" %(Jgen/10**-7)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.6 , Page number 245"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 25,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Nd= 2.55*10**15 cm**-3\n",
+      "\n",
+      "Na= 1.01*10**15 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Jn=20 #in A/cm**2\n",
+    "Jp=5 #in A/cm**2\n",
+    "Va=0.65 #in V\n",
+    "Dn=25 #in cm**2/s\n",
+    "Dp=10 #/in cm**2/s\n",
+    "tau_n0=5*10**-7 #in s\n",
+    "tau_p0=5*10**-7 #in s\n",
+    "epsilon_r=11.8 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "e=1.6*10**-19 #in eV\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Const=0.0259 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Lp=math.sqrt(Dp*tau_p0) #in cm\n",
+    "pn0=(Jp*Lp)/(e*Dp*(math.exp(Va/Const)-1)) #law of mass action in cm**-3\n",
+    "Nd=(ni**2/pn0)\n",
+    "Ln=math.sqrt(Dn*tau_n0) #in cm\n",
+    "np0=(Jn*Ln)/(e*Dn*(math.exp((Va/Const))-1)) #in cm**-3\n",
+    "Na=ni**2/np0 \n",
+    "\n",
+    "#Result\n",
+    "print(\"Nd= %1.2f*10**15 cm**-3\\n\" %(Nd/10**15)) #The answers vary due to round off error\n",
+    "print(\"Na= %1.2f*10**15 cm**-3\" %(Na/10**15))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.7 , Page number 246"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Minority carrier hole concentration= 2.59*10**14 cm**-3\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Nd=1*10**16 #n-type doping in cm**-3\n",
+    "V=0.6 #forward bias current in V\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Const=0.0259 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Pn0=ni**2/Nd #in cm**-3\n",
+    "Pn=Pn0*math.exp(V/Const)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Minority carrier hole concentration= %1.2f*10**14 cm**-3\" %(Pn/10**14))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.8 , Page number 247"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 39,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Current= 0.55 micro-Ampere\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Nd=5*10**16 #n-type doping in cm**-3\n",
+    "V=0.5 #forward bias current in V\n",
+    "e=1.6*10**-19 #in eV\n",
+    "tau_p=1*10**-6 #in s \n",
+    "Dp=10 #in cm**2/s\n",
+    "A=10**-3 #cross-sectional area in cm**2\n",
+    "Const=0.0259 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "pn=ni**2/Nd #in cm**-3\n",
+    "Lp=math.sqrt(Dp*tau_p) #in cm\n",
+    "I=e*A*(Dp/Lp)*pn*(math.exp(V/Const))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Current= %.2f micro-Ampere\" %(I/10**-6))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 6.9 , Page number 247"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Electric field value= 2.07 V/cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Na=10**16 #doping density in cm**-3 \n",
+    "Nd=10**16 #in cm**-3 \n",
+    "tau_p0=5*10**-7 #in s \n",
+    "tau_n0=5*10**-7 #in s\n",
+    "Dn=25 #in cm**2/s\n",
+    "Dp=10 #in cm**2/s\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "myu_n=1350 #in cm**2/V*s\n",
+    "myu_p=450 #in cm**2/V*s \n",
+    "V=0.65 #in V\n",
+    "Const=0.0259 #constant for kT/e in V\n",
+    "\n",
+    "\n",
+    "#Calculations\n",
+    "pn0=ni**2/Nd #in cm**-3\n",
+    "np0=ni**2/Na #in cm**-3\n",
+    "Lp=math.sqrt(Dp*tau_p0) #in cm\n",
+    "Ln=math.sqrt(Dn*tau_n0) #in cm\n",
+    "Js=(((e*Dp*pn0)/Lp)+((e*Dn*pn0)/Lp)) #in A/cm**2\n",
+    "J=Js*(math.exp(V/Const)-1) #Total current density in A/cm**2\n",
+    "sigma=e*myu_n*Nd #in mho/cm\n",
+    "E=J/sigma\n",
+    "\n",
+    "#Result\n",
+    "print(\"Electric field value= %1.2f V/cm\" %E) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter7_e6YYQO5.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter7_e6YYQO5.ipynb
new file mode 100644
index 00000000..242910a9
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter7_e6YYQO5.ipynb
@@ -0,0 +1,459 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 7 : Metal - Semiconductor Junction and Hetero - junctions "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7.1 , Page number 266"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a) Ideal Schottky barrier height= 0.165 eV\n",
+      "\n",
+      "b) Built-in potential barrier= 0.925 V\n",
+      "\n",
+      "c) Space charge width at zero bias= 0.155*10**-4 cm\n",
+      "\n",
+      "d) maximum electric field= 11.96*10**4 V cm**-1\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=5*10**16 #Doping level of n-type silicon in cm**-3\n",
+    "Nc=2.8*10**19 #in cm**-3 \n",
+    "e=1.6*10**-19 #in J\n",
+    "phi_B0=1.09 #in eV\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_n=Const*math.log(Nc/Nd) #in eV\n",
+    "Vbi=(phi_B0-phi_n) #in eV\n",
+    "xn=((2*epsilon_r*epsilon_0*Vbi)/(e*Nd))**0.5\n",
+    "Emax=(e*Nd*xn)/(epsilon_r*epsilon_0)\n",
+    "\n",
+    "#Result\n",
+    "print(\"a) Ideal Schottky barrier height= %0.3f eV\\n\" %phi_n)\n",
+    "print(\"b) Built-in potential barrier= %0.3f V\\n\" %Vbi)\n",
+    "print(\"c) Space charge width at zero bias= %1.3f*10**-4 cm\\n\" %(xn/10**-4))\n",
+    "print(\"d) maximum electric field= %.2f*10**4 V cm**-1\" %round(Emax/10**4,2))#answer vary due to sound-off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7.2 , Page number 267"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Actual barrier height= 0.578 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=2.01*10**7 #Doping level of n-type silicon in cm**-3\n",
+    "Nc=2.8*10**19 #in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "slope=6*10**13 \n",
+    "Vbi=0.45 #in V\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Nd=2/(e*epsilon_r*epsilon_0*slope) #in cm**-3\n",
+    "phi_n=Const*math.log(Nc/Nd) #in V\n",
+    "phi_Bn=Vbi+phi_n\n",
+    "\n",
+    "#Result\n",
+    "print(\"Actual barrier height= %0.3f V\" %phi_Bn)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7.3 , Page number 267"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 25,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Schottkybarrier-lowering for Si-metal contact= 0.011 V\n",
+      "\n",
+      "maximum barrier height= 5.54*10**-7 cm\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "E=10**4 #Electric field in V/cm\n",
+    "e=1.6*10**-19 #in J\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm         \n",
+    "\n",
+    "#Calculations\n",
+    "del_phi=math.sqrt((e*E)/(4*math.pi*epsilon_r*epsilon_0))\n",
+    "xm=math.sqrt(e/(16*math.pi*epsilon_r*epsilon_0*E))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Schottkybarrier-lowering for Si-metal contact= %0.3f V\\n\" %del_phi)\n",
+    "print(\"maximum barrier height= %1.2f*10**-7 cm\" %(xm/10**-7))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 7.4 , Page number 268"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Reverse saturation current density= 2.06*10**-7 A/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "A=114 #effective Richardson constant A/K**2*cm**2\n",
+    "e=1.6*10**-19 #in J\n",
+    "T=300 #in K\n",
+    "phi_Bn=0.82 #in eV\n",
+    "const=0.026 #value for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "J0=A*T**2*math.exp(-(phi_Bn/const))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Reverse saturation current density= %1.2f*10**-7 A/cm**2\" %(J0/10**-7))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number  7.5 , Page number 272"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Conduction band= 0.06 eV\n",
+      "\n",
+      "Valence band= 0.69 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "xGe=4.13  #in eV\n",
+    "xGaAs=4.07 #in eV\n",
+    "Eg_Ge=0.7 #in eV\n",
+    "Eg_GaAs=1.45 #in eV\n",
+    "\n",
+    "#Calculations\n",
+    "delE_c=xGe-xGaAs\n",
+    "delE_v=(Eg_GaAs-Eg_Ge)-delE_c\n",
+    "\n",
+    "#Result\n",
+    "print(\"Conduction band= %1.2f eV\\n\" %delE_c)\n",
+    "print(\"Valence band= %1.2f eV\" %delE_v)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number  7.6 , Page number 272"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 35,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a)\n",
+      "\n",
+      "ideal schottky barrier height= 0.49 ev\n",
+      "\n",
+      "b)\n",
+      "\n",
+      "peak electric field= 6.81*10**4 V/cm\n",
+      "\n",
+      "c)\n",
+      "\n",
+      "depletion layer capacitance per unit area= 7.05*10**-9 F/cm**2\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=3*10**15 #Doping level of n-type silicon in cm**-3\n",
+    "Nc=2.8*10**19 #in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "phi_m=4.5 #work function for chromium in eV\n",
+    "epsilon_si=11.7 #in F/cm\n",
+    "epsilon_0=8.854*10**-14 #in F/cm\n",
+    "xsi=4.01 #electron affinity for Si in eV\n",
+    "Vbi=5 #reverse bias voltage in V\n",
+    "VR=0 #in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_B=phi_m-xsi #in eV\n",
+    "xn=((2*epsilon_si*epsilon_0*(Vbi+VR))/(e*Nd))**0.5 #in cm\n",
+    "Emax=(e*Nd*xn)/(epsilon_si*epsilon_0)\n",
+    "CJ=((e*epsilon_si*epsilon_0*Nd)/(2*(Vbi+VR)))**0.5\n",
+    "\n",
+    "#Result\n",
+    "print(\"a)\\n\")\n",
+    "print(\"ideal schottky barrier height= %1.2f ev\\n\" %phi_B)\n",
+    "print(\"b)\\n\")\n",
+    "print(\"peak electric field= %1.2f*10**4 V/cm\\n\" %(Emax/10**4))\n",
+    "print(\"c)\\n\")\n",
+    "print(\"depletion layer capacitance per unit area= %1.2f*10**-9 F/cm**2\" %(CJ/10**-9)) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number  7.9 , Page number 272"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 37,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Energy state difference= 0.407 eV\n",
+      "\n",
+      " a)phi_s= 4.957 eV\n",
+      "\n",
+      " b)Forward Bias (phi_B)= 0.3 eV\n",
+      "\n",
+      "   eV0= 0.657 eV\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "phi_m=4.3 #work function in eV\n",
+    "xsi=4 #electron affinity in eV\n",
+    "p0=10**17 #in cm**-3\n",
+    "Na=10**17 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "delE_fc=0.957 #in eV\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "\n",
+    "#Calculations\n",
+    "delE_if=Const*math.log(p0/ni)\n",
+    "\n",
+    "#a) Before contact\n",
+    "phi_s=xsi+delE_fc \n",
+    "\n",
+    "#b) After contact\n",
+    "phi_B=phi_m-xsi \n",
+    "eV0=phi_s-phi_m\n",
+    "\n",
+    "#Result\n",
+    "print(\"Energy state difference= %.3f eV\\n\" %delE_if)\n",
+    "print(\" a)phi_s= %.3f eV\\n\" %phi_s)\n",
+    "print(\" b)Forward Bias (phi_B)= %.1f eV\\n\" %phi_B)\n",
+    "print(\"   eV0= %.3f eV\" %eV0) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number  7.9 , Page number 272"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 41,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "electron doping concentration = 4.1*10**10 cm**-3\n",
+      "\n",
+      "workfuntion of the semiconductor = 4.34 eV\n",
+      "\n",
+      "workfuntion of the semiconductor on B side = 4.89 eV\n",
+      "\n",
+      "workfuntion of the semiconductor at 400K = 4.74 eV \n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "delE_iF=0.0259 #in eV\n",
+    "delE_cF=0.29 #in eV\n",
+    "phi_G=4.8 #in eV\n",
+    "impurity_conc=9.9*10**14 #in cm**-3\n",
+    "affinity=0.55 #in eV\n",
+    "Const=0.0259 #constant value for kT in eV\n",
+    "x=4.05 #electron affinity for silicon in eV\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "n0=ni*math.exp(delE_iF/Const) #in cm**-3\n",
+    "phi_s=x+delE_cF \n",
+    "\n",
+    "#b)\n",
+    "Ptype_conc=impurity_conc-n0 #net concentration of p-type on B side in cm**-3\n",
+    "delE_iF_Bside=Const*math.log(Ptype_conc/ni) #in eV\n",
+    "phi_s_Bside=x+delE_iF_Bside+affinity\n",
+    "\n",
+    "#d)\n",
+    "ni1=8*10**12 #increased ni in cm**-3\n",
+    "delE_iF1=Const*math.log(n0/ni1) #in eV\n",
+    "phi_s1=x+(affinity-delE_iF1)\n",
+    "eV0=phi_s-phi_m\n",
+    "\n",
+    "#Result\n",
+    "print(\"electron doping concentration = %.1f*10**10 cm**-3\\n\" %(n0/10**10)) #The answer provided in the textbook is wrong\n",
+    "print(\"workfuntion of the semiconductor = %.2f eV\\n\" %phi_s)\n",
+    "print(\"workfuntion of the semiconductor on B side = %.2f eV\\n\" %phi_s_Bside) #The answer provided in the textbook is wrong\n",
+    "print(\"workfuntion of the semiconductor at 400K = %.2f eV \" %phi_s1) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter8_ZfKCkQQ.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter8_ZfKCkQQ.ipynb
new file mode 100644
index 00000000..8f45a209
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter8_ZfKCkQQ.ipynb
@@ -0,0 +1,304 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 8 : Bipolar Junction Transistors"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.1 , Page number "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "common-base current gain= 0.98\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "iC=21 #collector current in mA\n",
+    "iE=21.4 #Emitter current in mA\n",
+    "\n",
+    "#Calculations\n",
+    "alpha=iC/iE\n",
+    "\n",
+    "#Result\n",
+    "print(\"common-base current gain= %1.2f\" %alpha)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.2 , Page number 297"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Excess minority carrier concentration at x=WB/3 = 3.16*10**13 cm**-3\n",
+      "\n",
+      "Excess minority carrier concentration at x=0 = 4.74*10**13 cm**-3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ni=1.5*10**10 #in cm**3\n",
+    "Na=5*10**16 #in cm**3\n",
+    "Nd=5*10**18 #in cm**3\n",
+    "VBE=0.6 #in V\n",
+    "WB=3*10**-4 #in cm\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "#a)\n",
+    "np0=ni**2/Na #in cm**-3\n",
+    "deln_x=(np0/WB)*(((math.exp(VBE/Const)-1)*(2/3*WB))-WB/3)\n",
+    "\n",
+    "#b)\n",
+    "deln_x1=(np0/WB)*(math.exp(VBE/Const)-1)*WB\n",
+    "\n",
+    "#Result\n",
+    "print(\"Excess minority carrier concentration at x=WB/3 = %1.2f*10**13 cm**-3\\n\" %round(deln_x/10**13,2)) #The answers vary due to round off error\n",
+    "print(\"Excess minority carrier concentration at x=0 = %1.2f*10**13 cm**-3\\n\" %round(deln_x1/10**13,2)) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.3 , Page number 315"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Collector-emitter voltage at saturation= 0.16 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "alpha_F=0.98\n",
+    "alpha_R=0.18\n",
+    "IC=2 #current in mA\n",
+    "IB=0.06 #current in mA\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "VCE=Const*math.log((((IC*(1-alpha_R))+IB)/((alpha_F*IB)-((1-alpha_F)*IC)))*(alpha_F/alpha_R))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Collector-emitter voltage at saturation= %1.2f V\" %VCE)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.4 , Page number 315"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Transconductannce= 0.025 mho\n",
+      "\n",
+      "Voltage gain= -75\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "RL=3 #load resistor in ohm\n",
+    "hie=1*10**3 #in ohm\n",
+    "hre=2*10**-4 #in mho\n",
+    "hfe=25 #in mho\n",
+    "hoe=15*10**-6 #in mho\n",
+    "\n",
+    "#Calculations\n",
+    "gm=hfe/hie \n",
+    "Ave=-gm*RL*10**3\n",
+    "\n",
+    "#Result\n",
+    "print(\"Transconductannce= %0.3f mho\\n\" %gm)\n",
+    "print(\"Voltage gain= %0.2i\" %Ave)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.5 , Page number 316"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Total emitter-to-collector delay time= 84.6 ps\n",
+      "\n",
+      "cut-of frequency of transistor= 1.88 GHz\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "IE=1.5*10**-3 #in mA\n",
+    "Cje=1.2*10**-12 #in F\n",
+    "Dn=25 #in cm**2/s\n",
+    "WB=0.4*10**-4 #in cm\n",
+    "Wdc=2.5*10**-4 #in cm\n",
+    "vs=10**7 #in cm/s\n",
+    "Rc=25 #in ohm\n",
+    "CBC=0.15*10**-12 #in F\n",
+    "CS=0.12*10**-12 #in F\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Re=Const*(1/IE) #in ohm\n",
+    "tau_e=Re*Cje #emitter-base junction charging in s\n",
+    "tau_b=WB**2/(2*Dn) #transit time in the base in s\n",
+    "tau_d=Wdc/vs #collector depletion region transit time in s\n",
+    "tau_c=Rc*(CBC+CS) #collector capacitance charging time in s\n",
+    "tau_D=tau_e+tau_b+tau_d+tau_c\n",
+    "fT=1/(2*math.pi*(tau_D))\n",
+    "\n",
+    "\n",
+    "#Result\n",
+    "print(\"Total emitter-to-collector delay time= %0.1f ps\\n\" %round(tau_D/10**-12,1))\n",
+    "print(\"cut-of frequency of transistor= %0.2f GHz\" %round(fT/10**9,2))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 8.7 , Page number 319"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a) upper frequency limit= 1.91 GHz\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Wb=0.5*10**-6 #width of base region in m\n",
+    "Dp=15*10**-4 # in m**2/s\n",
+    "\n",
+    "#Calculations\n",
+    "tau_n=Wb**2/(2*Dp) #in s\n",
+    "tau_B=tau_n #in s\n",
+    "fT=1/(2*math.pi*tau_B)\n",
+    "\n",
+    "\n",
+    "#Result\n",
+    "print(\"a) upper frequency limit= %1.2f GHz\" %round(fT/10**9,2))"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter9_eHYvPeL.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter9_eHYvPeL.ipynb
new file mode 100644
index 00000000..6dec3b62
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/Chapter9_eHYvPeL.ipynb
@@ -0,0 +1,376 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#  Chapter 9 : Field-effect Transistor"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.1 , Page number 335"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "a) Pitch-off voltage= 55.6 V\n",
+      "\n",
+      "b) Pitch-off current= 640.8*10**-3 A\n",
+      "\n",
+      "c) Drain current at pinch-off= 203*10**-3 A\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Nd=5*10**16 #in cm**-3\n",
+    "Na=10**19 #in cm**-3 \n",
+    "d=1.2*10**-4 #in cm\n",
+    "e=1.6*10**-19# in J\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "L=18*10**-4 #in cm\n",
+    "W=80*10**-4 #in micro-W\n",
+    "myu_n=1350 #in cm**2/V*s\n",
+    "ni=1.5*10**10 #in cm**3\n",
+    "VGS=0 #in V\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Vp=(e*Nd*d**2)/(2*epsilon_r*epsilon_0) #Pitch-off voltage in V\n",
+    "Ip=(W*myu_n*e**2*Nd**2*d**3)/(epsilon_r*epsilon_0*L) #Pitch-off current in A\n",
+    "Vbi=Const*math.log((Na*Nd)/ni**2) #in V\n",
+    "ID=Ip*(1/3-((VGS+Vbi)/Vp)+(2/3)*((VGS+Vbi)/Vp)**3/2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"a) Pitch-off voltage= %1.1f V\\n\" %Vp)\n",
+    "print(\"b) Pitch-off current= %.1f*10**-3 A\\n\" %(Ip*10**3))\n",
+    "print(\"c) Drain current at pinch-off= %i*10**-3 A\" %(ID*10**3)) #The answers vary dueto round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.2 , Page number 336"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Channel thickness= 0.476 micro-m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19 #in eV\n",
+    "epsilon_r=13.1 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Nc=4.7*10**17 #in cm**-3\n",
+    "Nd=3*10**15 #in cm**-3\n",
+    "phi_Bn=0.9 #barrier height in V\n",
+    "VT=0.3 #threshold voltage in V\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_n=Const*math.log(Nc/Nd) #in V\n",
+    "Vbi=phi_Bn-phi_n #built-in voltage in V\n",
+    "Vp=Vbi-VT #pinch-off voltage in V\n",
+    "d=math.sqrt((2*epsilon_r*epsilon_0*Vp)/(e*Nd))\n",
+    "\n",
+    "#Result\n",
+    "print(\"Channel thickness= %0.3f micro-m\" %round(d/10**-4,3))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.3 , Page number 358"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Maximum space-charge width= 0.142 micro-meter\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19 #in J\n",
+    "epsilon_r=11.7 #in F/cm\n",
+    "epsilon_0=8.85*10**-14 #in F/cm\n",
+    "Na=5*10**16 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_pF=Const*math.log(Na/ni) #in V\n",
+    "WdT=((4*epsilon_r*epsilon_0*phi_pF)/(e*Na))**0.5\n",
+    "\n",
+    "#Result\n",
+    "print(\"Maximum space-charge width= %0.3f micro-meter\" %round(WdT/10**-4,3))\n",
+    "#The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.4 , Page number 359"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "work-function difference= -0.894 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "phi_m=3.20 #in V\n",
+    "Na=10**15 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "x=3.25\n",
+    "Eg=1.11 #in eV\n",
+    "e=1.6*10**-19 #in J\n",
+    "Const=0.026 #constant for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_pF=Const*math.log(Na/ni) #in V\n",
+    "phi_ms=(phi_m-(x+(Eg/2)+phi_pF))\n",
+    "\n",
+    "#Result\n",
+    "print(\"work-function difference= %0.3f V\" %phi_ms)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.5 , Page number 360"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Channel width= 14.9 micro-m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "ID_sat=5*10**-3 #in mA\n",
+    "L=1.3*10**-4 #in micro-m\n",
+    "myu_n=660 #in cm**2/V*s\n",
+    "Cox=7*10**-8 #in F/cm**2\n",
+    "VGS=5 #in V\n",
+    "VT=0.66 #in V\n",
+    "\n",
+    "#Calculations\n",
+    "Z=(ID_sat*2*L)/(myu_n*Cox*(VGS-VT)**2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Channel width= %.1f micro-m\" %round(Z/10**-4,1))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.6 , Page number 362"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Voltage of n-channel Si(1)= 1.03 V\n",
+      "\n",
+      "Voltage of n-channel Si(2)= 2.513 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "epsilon_0=8.854*10**-14 #in F/cm\n",
+    "epsilon_r=11.8 #in F/cm\n",
+    "epsilon_i=3.9 #in F/cm\n",
+    "d=100*10**-8 #gate oxide thickness in cm\n",
+    "phi_ms=-1.5 #in V\n",
+    "Qi=5*10**10*1.6*10**-19 #fixed oxide charge in C/cm**2\n",
+    "Na=10**18 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "VB=2.5 #in V\n",
+    "const=0.0259 #value for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "Ci=(epsilon_0*epsilon_i)/d #in F/cm**2\n",
+    "VFB=phi_ms-(Qi/Ci) #in V\n",
+    "phi_F=const*math.log(Na/ni) #in V\n",
+    "W=math.sqrt((2*epsilon_0*epsilon_r*(2*phi_F))/(e*Na)) #in cm\n",
+    "Qd=-e*Na*W #in C\n",
+    "VT=VFB+(2*phi_F)-(Qd/Ci) #in V\n",
+    "Wm=math.sqrt((2*epsilon_0*epsilon_r*((2*phi_F)+VB))/(e*Na)) #in cm\n",
+    "Qd1=-e*Na*Wm #in C\n",
+    "VT1=VFB+(2*phi_F)-(Qd1/Ci) #in V\n",
+    "\n",
+    "#Result\n",
+    "print(\"Voltage of n-channel Si(1)= %1.2f V\\n\" %VT)\n",
+    "print(\"Voltage of n-channel Si(2)= %1.3f V\" %VT1) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 9.7 , Page number 363"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Voltage of n-channel= -1.98 V\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing module\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "epsilon_0=8.854*10**-14 #in F/cm\n",
+    "epsilon_r=11.8 #in F/cm\n",
+    "epsilon_i=3.9 #in F/cm\n",
+    "d=80*10**-8 #gate oxide thickness in cm\n",
+    "phi_ms=-0.15 #work-function difference in V\n",
+    "Qi=10**11*1.6*10**-19 #fixed oxide charge in C/cm**2\n",
+    "Nd=5*10**17 #in cm**-3\n",
+    "ni=1.5*10**10 #in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "const=0.0259 #value for kT/e in V\n",
+    "\n",
+    "#Calculations\n",
+    "phi_F=const*math.log(Nd/ni) #in V \n",
+    "Wm=2*math.sqrt((epsilon_0*epsilon_r*abs(phi_F))/(e*Nd)) #in cm\n",
+    "Qd=e*Nd*Wm #depletion charges in C\n",
+    "Ci=(epsilon_0*epsilon_i)/d #in F/cm**2\n",
+    "VT=phi_ms-(Qi/Ci)-(Qd/Ci)-(2*phi_F)\n",
+    "\n",
+    "#Result\n",
+    "\n",
+    "print(\"Voltage of n-channel= %1.2f V\" %VT)"
+   ]
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter13_O3kovtd.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter13_O3kovtd.ipynb
new file mode 100644
index 00000000..c0e79f73
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter13_O3kovtd.ipynb
@@ -0,0 +1,227 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 13 : MICROWAVE DEVICES"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 13.1, Page number 480"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 31,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Drift velocity= 1*10**7\n",
+      "current density= 320.000000 A/cm**2\n",
+      "negative electron mobility= -3124 cm**2/Vs\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "l=10*10**-6 #length in m\n",
+    "f=10*10**9 #frequency in Hz\n",
+    "n=2*10**14 # n type doping concentration in cm**-3\n",
+    "e=1.6*10**-19 #in J\n",
+    "E=3200 #electric field in V/cm\n",
+    "\n",
+    "#Calculatiions\n",
+    "vd=l*f*10**2 #converting from m**2 to cm**2\n",
+    "J=e*n*vd\n",
+    "myu=-vd/E\n",
+    "\n",
+    "#Result\n",
+    "print(\"Drift velocity= %.0f*10**7 cms**-1\" %round(vd/10**7,0))\n",
+    "print(\"current density= %f A/cm**2\" %J) \n",
+    "print(\"negative electron mobility= %d cm**2/Vs\" %myu) #The answer provided in the textbook is wrong"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Example number 13.2, Page number 481"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 32,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Drift time= 1*10**-11 s\n",
+      "Operating frequency= 50 GHz\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "drift_length=2*10**-4 #in cm\n",
+    "drift_velocity=2*10**7 #in cm/s\n",
+    "\n",
+    "#Calculatiions\n",
+    "d=drift_length/drift_velocity\n",
+    "f=(drift_velocity*10**-2)/(2*drift_length*10**-2)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Drift time= %.0f*10**-11 s\" %round(d*10**11,0))\n",
+    "print(\"Operating frequency= %.0f GHz\" %round(f/10**9,0))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Example number 13.3, Page number 487"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 36,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "avalanche-zone velocity is= 6.25*10**7 cm/s\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "J=20*10**3 #in kA/cm**2\n",
+    "e=1.6*10**-19 #in C\n",
+    "Nd=2*10**15 #in cm**-3\n",
+    "\n",
+    "#Calculatiions\n",
+    "vz=J/(e*Nd)\n",
+    "\n",
+    "#Result\n",
+    "print(\"avalanche-zone velocity is= %.2f*10**7 cm/s\" %(vz/10**7))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Example number 13.4, Page number 488"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 44,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Breakdown voltage is= 154.37 V\n",
+      "Breakdown electric field is=2.57*10**5 V/m\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Nd=2.8*10**21 # donor doping concentration in m**-3\n",
+    "L=6*10**-6 #length in m\n",
+    "epsilon_s=8.854*10**-12*11.8 # in F/m\n",
+    "\n",
+    "#Calculatiions\n",
+    "Vbd=(e*Nd*L**2)/epsilon_s\n",
+    "Ebd=Vbd/L\n",
+    "\n",
+    "#Result#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "e=1.6*10**-19 #in eV\n",
+    "Nd=2.8*10**21 # donor doping concentration in m**-3\n",
+    "L=6*10**-6 #length in m\n",
+    "epsilon_s=8.854*10**-12*11.8 # in F/m\n",
+    "\n",
+    "#Calculatiions\n",
+    "Vbd=(e*Nd*L**2)/epsilon_s\n",
+    "Ebd=Vbd/L\n",
+    "\n",
+    "#Result\n",
+    "print(\"Breakdown voltage is= %.2f V\" %Vbd)#The answers vary due to round off error\n",
+    "print(\"Breakdown electric field is=%.2f*10**5 V/m\" %round(Ebd/10**7,2))\n",
+    "print(\"Breakdown voltage is= %.2f V\" %Vbd)#The answers vary due to round off error\n",
+    "print(\"Breakdown electric field is=%.2f*10**5 V/m\" %round(Ebd/10**7,2))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter14_Tw2n7GH.ipynb b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter14_Tw2n7GH.ipynb
new file mode 100644
index 00000000..ead244bb
--- /dev/null
+++ b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/chapter14_Tw2n7GH.ipynb
@@ -0,0 +1,218 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Chapter 14 : Rectifiers and Power Supplies"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14.1, Page number 507"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(a)Maximum current Im is (A)=  20.0 mA\n",
+      "(b)dc component of current Idc is (A)= 6.37*10**-3 A\n",
+      "(c)rms value of current Irms (A)=  10.0 mA\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Vm=100     #voltage in V\n",
+    "Rf=1*10**3 #resistance in series in ohm\n",
+    "Rl=4*10**3 #load resistance in ohm\n",
+    "\n",
+    "#Calculatiions\n",
+    "Im=Vm/(Rf+Rl)*10**3\n",
+    "Idc=Im/math.pi\n",
+    "Irms=Im/2\n",
+    "\n",
+    "#Result\n",
+    "print(\"(a)Maximum current Im is (A)= \",Im,\"mA\")\n",
+    "print(\"(b)dc component of current Idc is (A)= %0.2f*10**-3 A\" %Idc)\n",
+    "print(\"(c)rms value of current Irms (A)= \",Irms,\"mA\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14.2, Page number 508"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(a)Maximum current Im= 0.133 A\n",
+      "\n",
+      "(b)dc component of current Idc= 0.0849 A\n",
+      "\n",
+      "(c)rms value of current Irms= 0.094 A\n",
+      "\n",
+      "(d)Ripple Factor Y= 0.483\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "Vm=200 #voltage in V\n",
+    "Rf=500 #resistance in series in ohm\n",
+    "Rl=1000 #load resistance in ohm\n",
+    "\n",
+    "#Calculatiions\n",
+    "Im=Vm/(Rf+Rl) \n",
+    "Idc=(2*Im)/math.pi\n",
+    "Irms=Im/math.sqrt(2)\n",
+    "Y=math.sqrt(((Irms/Idc)**2)-1)\n",
+    "\n",
+    "#Result\n",
+    "print(\"(a)Maximum current Im= %0.3f A\\n\" %Im)\n",
+    "print(\"(b)dc component of current Idc= %1.4f A\\n\" %Idc)\n",
+    "print(\"(c)rms value of current Irms= %1.3f A\\n\" %Irms)\n",
+    "print(\"(d)Ripple Factor Y= %1.3f\" %Y) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14.3, Page number 509"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Ripple factor Y= 0.00056\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "RL=500        #load resistance in ohm\n",
+    "C1=100*10**-6 #capacitance in F\n",
+    "C2=50*10**-6  #capacitance in F\n",
+    "L=5           #in H\n",
+    "f=50          #frequency in Hz\n",
+    "\n",
+    "#Calculatiions\n",
+    "Y=0.216/(RL*C1*C2*L*(2*math.pi*f)**3)\n",
+    "\n",
+    "#Result\n",
+    "print(\"Ripple factor Y= %0.5f\" %Y) #The answers vary due to round off error"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Example number 14.4, Page number 517"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Minimum Power Rating p= 37.3 W\n"
+     ]
+    }
+   ],
+   "source": [
+    "#importing modules\n",
+    "import math\n",
+    "from __future__ import division\n",
+    "\n",
+    "#Variable declaration\n",
+    "\n",
+    "Iz_min=1492.5*10**-3 #Zener diode current in Ampere\n",
+    "Vz=25                #Zener diode voltage in Volt\n",
+    "\n",
+    "#Calculatiions\n",
+    "Pmin=Vz*Iz_min\n",
+    "\n",
+    "#Result\n",
+    "print(\"Minimum Power Rating p= %2.1f W\" %Pmin)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [Root]",
+   "language": "python",
+   "name": "Python [Root]"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
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diff --git a/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/screenshots/Chapter5_KmacWXe.png b/Solid_State_Electronic_Devices_by_D.K_Bhattacharya_,_Rajnish_Sharma/screenshots/Chapter5_KmacWXe.png
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