{ "metadata": { "name": "", "signature": "sha256:cd8528b1343f720ba16c3255f8c2f531a0d8db6500634023001bba60d12d390a" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 5:Principles of Quantum Mechanics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.1, Page number 5.12" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Varaible declaration\n", "c = 3*10**8 #velocity of air(m/s)\n", "m = 1.67*10**-27 #mass of proton(kg)\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "\n", "#Calculation\n", "v = c/10. #velocity of proton(m/s)\n", "lamda = h/(m*v)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",round((lamda/1E-14),3),\"*10^-14 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 1.323 *10^-14 m\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.2, Page number 5.12" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Varaible declaration\n", "V = 400 #potential(V)\n", "\n", "#Calculation\n", "lamda = 12.26/math.sqrt(V)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",lamda,\"A\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 0.613 A\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.3, Page number 5.12" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Varaible declaration\n", "E = 0.025 #kinetic energy of neutron(eV)\n", "m = 1.674*10**-27 #mass of neutron(kg)\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "\n", "#Calculations\n", "E_j = E*1.6*10**-19 #converting eV to joules\n", "lamda = h/math.sqrt(2*m*E_j)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",round((lamda/1E-11),3),\"*10^-11 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 18.106 *10^-11 m\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.4, Page number 5.13" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Varaible declaration\n", "V = 1600 #potential(V)\n", "\n", "#Calculation\n", "lamda = 12.26/math.sqrt(V)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",lamda,\"A\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 0.3065 A\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.5, Page number 5.21" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Varaible declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "L = 0.1*10**-9 #length of each side of box(m)\n", "#For lowest energy level,\n", "nx = 1\n", "ny = 1\n", "nz = 1\n", "\n", "#Calculations\n", "E1 = (((h**2)*(nx**2+ny**2+nz**2))/(8*m*L**2))/(1.6*10**-19)\n", "\n", "#Result\n", "print \"The lowest energy of electron is\",round(E1,2),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The lowest energy of electron is 113.08 eV\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.6, Page number 5.22" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "L = 0.1*10**-9 #length of each side of box(m)\n", "#For level next to lowest energy level,\n", "nx = 1\n", "ny = 1\n", "nz = 2\n", "\n", "#Calculations\n", "E1 = (((h**2)*(nx**2+ny**2+nz**2))/(8*m*L**2))/(1.6*10**-19)\n", "\n", "#Result\n", "print \"The lowest energy of electron is\",round(E1,2),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The lowest energy of electron is 226.15 eV\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.7, Page number 5.23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "E = 2000. #energy of electron(eV)\n", "\n", "#Calculations\n", "Ej = E*1.6*10**-19 #converting eV to joules\n", "lamda = h/math.sqrt(2*m*Ej)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",round((lamda/1E-9),4),\"nm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 0.0275 nm\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.8, Page number 5.23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "L = 4*10**-10 #length of each side of box(m)\n", "#For minimum energy \n", "n = 1\n", "\n", "#Calculations\n", "E1 = ((h**2)*(n**2))/(8*m*L**2)\n", "\n", "#Result\n", "print \"Minimum energy =\",round((E1/1E-18),3),\"*10^-18 J\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Minimum energy = 0.377 *10^-18 J\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.9, Page number 5.24" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "L = 1*10**-10 #length of each side of box(m)\n", "n1 = 10 #For energy in ground state\n", "n2 = 2 #For energy in first excited state\n", "n3 = 3 #For energy in second excited state\n", "\n", "#Calculations\n", "E1 = ((h**2)*(n1**2))/(8*m*L**2)\n", "E2 = ((h**2)*(n2**2))/(8*m*L**2)\n", "E3 = ((h**2)*(n3**2))/(8*m*L**2)\n", "\n", "#Results\n", "print \"Energy in ground state =\",round((E1/1E-17),4),\"*10^17 J (Calculation mistake in textbook)\"\n", "print \"Energy in first excited state =\",round((E2/1E-17),4),\"*10^17 J\"\n", "print \"Energy in second excited state =\",round((E3/1E-17),4),\"*10^17 J\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy in ground state = 60.3075 *10^17 J (Calculation mistake in textbook)\n", "Energy in first excited state = 2.4123 *10^17 J\n", "Energy in second excited state = 5.4277 *10^17 J\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.10, Page number 5.24" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "h = 6.626*10**-34 #Planck's constant(J x sec)\n", "m = 9.1*10**-31 #mass of electron(kg)\n", "lamda = 1.66*10**-10 #wavelength(m)\n", "\n", "#Calculations\n", "v = h/(m*lamda)\n", "KE = (m*v**2)/(2*1.6*10**-19) #in joules\n", "\n", "#Result\n", "print \"Velocity of electron =\",round((v/1E+7),4),\"*10^7 m\"\n", "print \"Kinetic energy of electron =\",round(KE,2),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity of electron = 0.4386 *10^7 m\n", "Kinetic energy of electron = 54.71 eV\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.11, Page number 5.25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Varaible declaration\n", "V = 15*10**3 #potential(V)\n", "\n", "#Calculation\n", "lamda = 12.26/math.sqrt(V)\n", "\n", "#Result\n", "print \"The de Brogile wavelength is\",round(lamda,2),\"A\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Brogile wavelength is 0.1 A\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5.12, Page number 5.25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Varaible declaration\n", "V = 344 #potential(V)\n", "theta = 60 #glancing angle(degrees)\n", "\n", "#Calculation\n", "lamda = 12.26/math.sqrt(V)\n", "#For first reflection \n", "n = 1\n", "d = (n*lamda)/(2*math.sin(math.radians(theta)))\n", "\n", "#Result\n", "print \"The interatomic spacing of the crystal is\",round(d,4),\"A\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The interatomic spacing of the crystal is 0.3816 A\n" ] } ], "prompt_number": 24 } ], "metadata": {} } ] }