{ "metadata": { "name": "", "signature": "sha256:9388f9d8764031d08c03b951ac3babfe1cafed91339d0e7cf1d9a5afd45176fa" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "5: Quantum Theory" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.1, Page number 97" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W1=4; #wavelength(Angstrom)\n", "W2=1; #wavelength(Angstrom)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "m=9.12*10**-31; #mass of electron(kg)\n", "\n", "#Calculation\n", "E=12400/W1; #energy(eV)\n", "v=math.sqrt(E*e*2/m); #velocity(m/s)\n", "E1=12400/W2; #energy(eV)\n", "v1=math.sqrt(E1*e*2/m); #velocity(m/s)\n", "\n", "#Result\n", "print \"The energy for 4 angstrom wavelength is\",E,\"eV\"\n", "print \"The velocity is\",round(v/1e+6),\"*10**6 m/s\"\n", "print \"The energy for 1 angstrom wavelength is\",E1,\"eV\"\n", "print \"The velocity is\",round(v1/1e+6),\"*10**6 m/s\"\n", "\n", "#answers given in the book are wrong" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The energy for 4 angstrom wavelength is 3100.0 eV\n", "The velocity is 33.0 *10**6 m/s\n", "The energy for 1 angstrom wavelength is 12400.0 eV\n", "The velocity is 66.0 *10**6 m/s\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.2, Page number 98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "f=880*10**3; #frequency(Hz)\n", "P=10*10**3; #Power(W)\n", "h=6.625*10**-34; #Plank's constant\n", "\n", "#Calculation\n", "E=h*f; #energy carried by each photon(J)\n", "n=P/E; #number of photons emitted per second\n", "\n", "#Result\n", "print \"The number of photons emitted per second are\",round(n/1e+30,2),\"*10**30\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The number of photons emitted per second are 17.15 *10**30\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.3, Page number 98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "P=200; #power(W)\n", "W=6123*10**-10; #wavelength(m)\n", "c=3*10**8; #speed of light(m/s)\n", "h=6.625*10**-34; #Plank's constant\n", "\n", "#Calculation\n", "Op=0.5*P; #radiant output(J/s)\n", "E=h*c/W; #energy content(J)\n", "n=2/E; #number of quanta emitted per second\n", "\n", "#Result\n", "print \"Number of quanta emitted per second is\",round(n/1e+18,2),\"*10**18\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Number of quanta emitted per second is 6.16 *10**18\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.4, Page number 98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "N=5*10**4; #no. of photons\n", "W=3000*10**-10; #wavelength(m)\n", "J=5*10**-3; #senstivity(A/W)\n", "h=6.625*10**-34; #Plank's constant\n", "c=3*10**8; #speed of light(m/s)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "\n", "#Calculation\n", "E=h*c/W; #energy content of each photon(J)\n", "TE=N*E; #total energy(J)\n", "I=J*TE; #current produced(ampere)\n", "n=I/e; #number of photo electrons ejected\n", "\n", "#Result\n", "print \"number of photoelectrons emitted are\",int(n)\n", "print \"answer given in the book varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "number of photoelectrons emitted are 1035\n", "answer given in the book varies due to rounding off errors\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.5, Page number 99" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=5*10**-7; #wavelength(m)\n", "F=10**-5; #force(N)\n", "h=6.625*10**-34; #Plank's constant\n", "m=1.5*10**-3; #mass(kg)\n", "c=3*10**8; #speed of light in (m/s)\n", "S=0.1; #specific heat\n", "\n", "#Calculation\n", "n=F*W/h; #number of photons\n", "E=F*c/4200; #energy of each photon(kcal/s)\n", "theta=E/(m*S); #rate of rise in temperature(C/s)\n", "\n", "#Result\n", "print \"number of photons are\",round(n/1e+21,3),\"*10**21\"\n", "print \"the rate of temperature rise is\",round(theta/1e+3,1),\"*10**3 C/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "number of photons are 7.547 *10**21\n", "the rate of temperature rise is 4.8 *10**3 C/s\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.6, Page number 99" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=4500*10**-10; #wavelength(m)\n", "V=150; #rated voltage(W)\n", "h=6.625*10**-34; #Plank's constant\n", "c=3*10**8; #speed of light(m/s)\n", "\n", "#Calculation\n", "P=V*8/100; #lamp power emitted(W)\n", "E=h*c/W; #energy carried by 1 photon(J) \n", "n=P/E; #number of photons emitted per second\n", "\n", "#Result\n", "print \"Number of photons emitted per second is\",round(n/1e+18,2),\"*10**18\"\n", "print \"answer given in the book varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Number of photons emitted per second is 27.17 *10**18\n", "answer given in the book varies due to rounding off errors\n" ] } ], "prompt_number": 30 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.7, Page number 99" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "f=1*10**12; #frequency(Hz)\n", "h=6.625*10**-34; #Plank's constant\n", "\n", "#Calculation\n", "E=h*f; #energy per photon(J)\n", "n=E/6.625; #number of photons\n", "\n", "#Result\n", "print \"the number of photons required is\",n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the number of photons required is 1e-22\n" ] } ], "prompt_number": 31 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.8, Page number 100" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=5200*10**-10; #wavelength(m)\n", "h=6.625*10**-34; #Plank's constant\n", "m=9.12*10**-31; #mass of electron(kg)\n", "\n", "#Calculation\n", "p=h/W; #momentum(kg-m/s)\n", "v=p/m; #velocity(m/s)\n", "\n", "#Result\n", "print \"velocity is\",round(v),\"m/s\"\n", "print \"answer given in the book varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "velocity is 1397.0 m/s\n", "answer given in the book varies due to rounding off errors\n" ] } ], "prompt_number": 33 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.9, Page number 105" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "v=7*10**5; #maximum speed(m/sec)\n", "f=8*10**14; #frequency(Hz)\n", "h=6.625*10**-34; #Plank's constant\n", "c=3*10**8; #speed of light(m/s)\n", "m=9.12*10**-31; #mass of electron(kg)\n", "\n", "#Calulation\n", "E=m*v*v/2; #energy(J)\n", "fo=f-(E/h); #threshold frequency of the surface(Hz) \n", "\n", "#Result\n", "print \"the threshold frequency is\",round(fo/1e+14,2),\"*10**14 Hz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the threshold frequency is 4.63 *10**14 Hz\n" ] } ], "prompt_number": 37 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.10, Page number 106" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "Wo=2300*10; #threshold wavelength(Angstrom)\n", "W=1800*10; #incident light wavelength(Angstrom)\n", "\n", "#Calculation\n", "w=124000/Wo; #maximum energy of photoelectrons emitted(eV)\n", "E=124000*((1/W)-(1/Wo)); #work function for tungsten(eV)\n", "\n", "#Result\n", "print \"maximum energy of photoelectrons emitted is\",round(w,1),\"eV\"\n", "print \"work function for tungsten is\",round(E,1),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "maximum energy of photoelectrons emitted is 5.4 eV\n", "work function for tungsten is 1.5 eV\n" ] } ], "prompt_number": 39 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.11, Page number 106" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=6000; #wavelegth(Angstrom)\n", "v=4*10**5; #velocity(m/sec)\n", "m=9.12*10**-31; #mass of electron(kg)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "\n", "#Calculation\n", "KE=m*v**2/(2*e); #kinetic energy of photo electronns(eV)\n", "WF=12400/W; #energy content of photon(eV)\n", "Wo=12400/(WF-KE); #photo electric threshold wavelength(angstrom)\n", "\n", "#Result\n", "print \"The Kinetic energy is\",KE,\"eV\"\n", "print \"The threshold wavelength is\",int(Wo),\"Angstrom\"\n", "print \"answer given in the book varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Kinetic energy is 0.456 eV\n", "The threshold wavelength is 7698 Angstrom\n", "answer given in the book varies due to rounding off errors\n" ] } ], "prompt_number": 43 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.12, Page number 106" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "Wo=4.8; #work function(eV)\n", "W=2220; #wavelength(angstrom)\n", "\n", "#Calculation\n", "E=12400/W; #energy of light photon(eV)\n", "Emax=E-Wo; #maximum kinetic energy(eV)\n", "\n", "#Result\n", "print \"maximum kinetic energy is\",round(Emax,3),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "maximum kinetic energy is 0.786 eV\n" ] } ], "prompt_number": 46 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.13, Page number 106" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=4000*10**-10; #wavelength(m)\n", "Vs=0.4; #retarding potential(eV)\n", "h=6.625*10**-34; #Plank's constant\n", "c=3*10**8; #speed of light(m/s)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "\n", "#Calculation\n", "f=c/W; #frequency of light(Hz)\n", "E=h*f/e; #photon energy(eV)\n", "Wo=E-Vs; #work function(eV)\n", "fo=Wo/h*e; #threshold frequency(Hz)\n", "NE=(E-Wo)*e; #net energy(J)\n", "\n", "#Result\n", "print \"The light frequency is\",f,\"Hz\"\n", "print \"The photon energy is\",round(E,1),\"eV\"\n", "print \"The work function is\",round(Wo,1),\"eV\"\n", "print \"The threshold frequency is\",round(fo/1e+14,1),\"*10**14 Hz\"\n", "print \"The net energy is\",NE,\"J\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The light frequency is 7.5e+14 Hz\n", "The photon energy is 3.1 eV\n", "The work function is 2.7 eV\n", "The threshold frequency is 6.5 *10**14 Hz\n", "The net energy is 6.4e-20 J\n" ] } ], "prompt_number": 51 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.14, Page number 107" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W1=3310*10**-10; #photon wavelength(m)\n", "W2=5000*10**-10; #photon wavelength(m)\n", "E1=3*10**-19; #electron energy(J)\n", "E2=0.972*10**-19; #electron energy(J)\n", "c=3*10**8; #speed of light in m/s\n", "\n", "#Calculation\n", "h=(E1-E2)*(W1*W2)/(c*(W2-W1)); #planck's constant(Js)\n", "Wo=c*h/E1; #threshold wavelength(m) \n", "\n", "#Result\n", "print \"the plancks const is\",round(h/1e-34,2),\"*10**-34 Js\"\n", "print \"The threshold wavelength is\",round(Wo*1e+10),\"*10**-10 m\"\n", "print \"answer given in the book is wrong\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the plancks const is 6.62 *10**-34 Js\n", "The threshold wavelength is 6620.0 *10**-10 m\n", "answer given in the book is wrong\n" ] } ], "prompt_number": 57 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.15, Page number 107" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=6525; #wavelength(angstrom)\n", "\n", "#Calculation\n", "Vo_a=12400*((1/4000)-(1/W)); #stopping potential(V)\n", "Vo_b=12400*((1/2000)-(1/W)); #stopping potential(V)\n", "Vo_c=12400*((1/2000)-(2/W)); #stopping potential(V)\n", "\n", "#Result\n", "print \"Stopping potential is\",round(Vo_a,1),\"Volt\"\n", "print \"Stopping potential is\",round(Vo_b,1),\"Volt\"\n", "print \"Stopping potential is\",round(Vo_c,1),\"Volt\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Stopping potential is 1.2 Volt\n", "Stopping potential is 4.3 Volt\n", "Stopping potential is 2.4 Volt\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.16, Page number 107" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "Wo=5000; #wavelength(angstrom)\n", "V=3.1; #stopping potential(V)\n", "\n", "#Calcultion\n", "W=1/((V/12400)+(1/Wo)); #wavelength(angstrom)\n", "\n", "#Result\n", "print \"The wavelength is\",int(W),\"Angstrom\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The wavelength is 2222 Angstrom\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.17, Page number 108" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "W=2000; #wavelength(Angstrom)\n", "Vs=4.2; #Work Function(eV)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "\n", "#Calculation\n", "E=12400/W; #photon energy(eV)\n", "Emax=(E-Vs)*e; #maximum kinetic energy(J)\n", "Emin=0; #minimum kinetic energy\n", "Vo=Emax/e; #stopping potential(V)\n", "Wo=12400/Vs; #cut off wavelength(angstrom)\n", "\n", "#Result\n", "print \"Kinetic Energy of fastest photoelectron is\",Emax,\"J\"\n", "print \"Kinetic Energy of slowest moving electron is\",Emin,\"J\"\n", "print \"Stopping potential is\",Vo,\"V\"\n", "print \"The cutoff wavelength is\",round(Wo,1),\"Angstrom\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Kinetic Energy of fastest photoelectron is 3.2e-19 J\n", "Kinetic Energy of slowest moving electron is 0 J\n", "Stopping potential is 2.0 V\n", "The cutoff wavelength is 2952.4 Angstrom\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.18, Page number 108" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#import modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "Vs1=4.6; #Stopping Potential(V)\n", "Vs2=12.9; #Stopping Potential(V)\n", "f1=2*10**15; #frequency(Hz)\n", "f2=4*10**15; #frequency(Hz)\n", "e=1.6*10**-19; #the charge on electron(C)\n", "\n", "#Calculation\n", "h=((Vs2-Vs1)*e)/(f2-f1); #planck's constant(Js)\n", "\n", "#Result\n", "print \"The Planck's constant is\",h,\"Js\"\n", "print \"answer given in the book is wrong\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Planck's constant is 6.64e-34 Js\n", "answer given in the book is wrong\n" ] } ], "prompt_number": 10 } ], "metadata": {} } ] }