{ "metadata": { "name": "", "signature": "sha256:9dafdb7acb5e988ab3a5ace98a3f2deebed0e1d539e288cbefca9baaaeda9388" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "10: Quantum Mechanics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.1, Page number 196" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "v=10**7; #speed of electron(m/s)\n", "h=6.626*10**-34; #plancks constant\n", "m=9.1*10**-31; #mass of electron(kg)\n", "\n", "#Calculation \n", "lamda=h/(m*v); #de Broglie wavelength(m)\n", "\n", "#Result\n", "print \"The de Broglie wavelength is\",round(lamda*10**11,2),\"*10**-11 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The de Broglie wavelength is 7.28 *10**-11 m\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.2, Page number 196" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #plancks constant\n", "lamda=0.3; #de Broglie wavelength(nm)\n", "#For electron\n", "me=9.1*10**-31; #mass of electron(kg)\n", "#For proton\n", "mp=1.672*10**-27; #mass of proton(kg)\n", "\n", "#Calculation \n", "p=h/(lamda*10**-9); #uncertainity in determining momentum(kg m/s)\n", "K1=p**2/(2*me); #kinetic energy of electron(J)\n", "K2=p**2/(2*mp); #kinetic energy of proton(J)\n", "\n", "#Result\n", "print \"The kinetic energy of electron is\",round(K1*10**18,1),\"*10**-18 J\"\n", "print \"The kinetic energy of proton is\",round(K2*10**21,2),\"*10**-21 J\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The kinetic energy of electron is 2.7 *10**-18 J\n", "The kinetic energy of proton is 1.46 *10**-21 J\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.3, Page number 196" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "#K=p^2/(lambda^2*2*m) where K is kinetic energy\n", "h=6.626*10**-34; #plancks constant\n", "lamda=10**-14; #de Broglie wavelength(m)\n", "m=9.1*10**-31; #mass of electron(kg)\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "K=(h**2/((lamda**2)*2*m*e))*10**-9; \n", "\n", "#Result\n", "print \"The kinetic energy is\",int(K),\"GeV\"\n", "print \"It is not possible to confine the electron to a nucleus.\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The kinetic energy is 15 GeV\n", "It is not possible to confine the electron to a nucleus.\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.4, Page number 197" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#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", "v=6*10**3; #speed of electron(m/s)\n", "h=6.626*10**-34; #plancks constant\n", "a=0.00005; \n", "\n", "#Calculation \n", "p=m*v; #uncertainity in momentum(kg m/s)\n", "deltap=a*p; #uncertainity in p\n", "deltax=(h/(4*math.pi*deltap))*10**3 #uncertainity in position(mm)\n", "\n", "#Result\n", "print \"The uncertainity in position is\",round(deltax,3),\"mm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The uncertainity in position is 0.193 mm\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.5, Page number 197" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "L=3*10**-5; #diameter of the sphere(nm)\n", "h=6.626*10**-34; #plancks constant\n", "m=1.67*10**-27; #mass of the particle(kg)\n", "n=1;\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "E1=((h**2)*(n**2))/(8*m*(L**2)*e)*10**12 #first energy level(MeV)\n", "E2=E1*2**2; #second energy level(MeV)\n", "\n", "#Result\n", "print \"The first energy level is\",round(E1,3),\"MeV\"\n", "print \"The second energy level is\",round(E2,4),\"MeV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The first energy level is 0.228 MeV\n", "The second energy level is 0.9128 MeV\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.6, Page number 197" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #plancks constant\n", "a=2*10**12; #angular frequency(rad/s)\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "E0=(0.5*(h/(2*math.pi*e))*a)*10**3; #ground state energy(MeV)\n", "E1=(1.5*(h/(2*math.pi*e))*a)*10**3; #first excited state energy(MeV)\n", "\n", "#Result\n", "print \"The ground state energy is\",round(E0,3),\"MeV\" \n", "print \"The first excited state energy is\",round(E1,3),\"MeV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The ground state energy is 0.659 MeV\n", "The first excited state energy is 1.977 MeV\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.7, Page number 197" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #plancks constant\n", "E=85; #Energy(keV)\n", "c=3*10**8; #speed of light(m/s)\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "lamda=(h*c)/(E*10**3*e); #de Broglie wavelength(m)\n", "m=9.1*10**-31; #mass of electron(kg)\n", "K=((h**2)/((lamda**2)*2*m*e)); #kinetic energy of electron(keV)\n", "\n", "#Result\n", "print \"The kinetic energy of the electron is\",round(K*10**-3,2),\"keV\"\n", "print \"answer in the book varies due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The kinetic energy of the electron is 7.06 keV\n", "answer in the book varies due to rounding off errors\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.8, Page number 198" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "lamda=0.08; #de Briglie wavelength(nm)\n", "m=9.1*10**-31; #mass of electron(kg)\n", "h=6.626*10**-34; #plancks constant\n", "\n", "#Calculation \n", "v=h/(m*lamda*10**-9); #velocity of the electron(m/s)\n", "\n", "#Result\n", "print \"The velocity of the electron is\",round(v/10**6,1),\"*10**6 m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The velocity of the electron is 9.1 *10**6 m/s\n" ] } ], "prompt_number": 28 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.9, Page number 198" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #plancks constant\n", "lamda=589*10**-9; #wavelength(m)\n", "m=9.1*10**-31; #mass of electron(kg)\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "V=((h**2)/((lamda**2)*2*m*e))*10**6; #potential diference(micro V)\n", "\n", "#Result\n", "print \"The potential difference through which an electron should be accelerated is\",round(V,2),\"micro V\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The potential difference through which an electron should be accelerated is 4.35 micro V\n" ] } ], "prompt_number": 31 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.10, Page number 198" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "deltax=0.92*10**-9; #uncertainity in position(m)\n", "m=9.1*10**-31; #mass of electron(kg)\n", "h=6.626*10**-34; #plancks constant\n", "\n", "#Calculation \n", "deltav=h/(4*math.pi*m*deltax); #uncertainity in velocity(m/s)\n", "\n", "#Result\n", "print \"The uncertainity in velocity is\",round(deltav/10**4,1),\"*10**4 m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The uncertainity in velocity is 6.3 *10**4 m/s\n" ] } ], "prompt_number": 33 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.11, Page number 198" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "h=6.626*10**-34; #plancks constant\n", "n=3; #for second excited state\n", "m=1.67*10**-27; #mass of proton(kg)\n", "E=0.5; #energy(MeV)\n", "e=1.6*10**-19;\n", "\n", "#Calculation \n", "L=((h*n)/math.sqrt(8*m*E*10**6*e))*10**15; #length of the box(fm)\n", "\n", "#Result\n", "print \"The length of the box for proton in its second excited state is\",round(L,1),\"fm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The length of the box for proton in its second excited state is 60.8 fm\n" ] } ], "prompt_number": 35 } ], "metadata": {} } ] }