{ "metadata": { "name": "", "signature": "sha256:38e4520c8655f11fdcb5696673580e95d36ab2ce43843aea287c93b1f1a0b257" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "10: Quantum Physics and Schrodinger wave equation" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.1, Page number 258" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#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=6.625*10**-34; #planck's constant(Jsec)\n", "deltax=10**-8; #uncertainity in position(m)\n", "\n", "#Calculation\n", "deltap=(h/(2*math.pi*deltax)); #uncertainity principle(kgm/sec)\n", "deltav=(deltap/me); #minimum uncertainity in velocity(m/sec)\n", "\n", "#Result\n", "print \"minimum uncertainity in velocity is\",round(deltav/10**5,3),\"*10**5 m/sec\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "minimum uncertainity in velocity is 0.116 *10**5 m/sec\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.2, Page number 259" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "lamda=0.2865*10**-10; #wavelength(m)\n", "mp=1.67*10**-27; #mass of proton(kg)\n", "h=6.625*10**-34; #planck's constant(Jsec)\n", "q=1.6*10**-19; #charge of proton(C)\n", "\n", "#Calculation\n", "v=(h/(mp*lamda)); #velocity(m/sec)\n", "KE=0.5*mp*(v**2); #kinetic energy of proton(J)\n", "KE=KE/q; #kinetic energy of proton(eV)\n", "\n", "#Result\n", "print \"kinetic energy of proton is\",int(KE),\"eV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "kinetic energy of proton is 1 eV\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.3, Page number 259" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "KE=0.025; #kinetic energy of neutron(eV)\n", "q=1.6*10**-19; #charge of proton(C)\n", "mn=1.676*10**-27; #mass of neutron(kg)\n", "h=6.625*10**-34; #planck's constant(Jsec)\n", "me=9.1*10**-31; #mass of electron(kg)\n", "c=3*10**8; #velocity of light(m/s)\n", "\n", "#Calculation\n", "KE=KE*q; #kinetic energy of neutron(J)\n", "v=math.sqrt((2*KE)/mn); #velocity(m/s)\n", "lamdan=h/(mn*v); #debroglie wavelength of neutron(m)\n", "p=(h/lamdan); #momentum of electron and photon(kgm/s)\n", "ve=(p/me); #velocity of electron(m/s)\n", "Ee=0.5*p*ve; #energy of electron(J)\n", "Ee=Ee/q; #energy of electron(eV)\n", "Ep=h*c/lamdan; #energy of photon(J)\n", "Ep=Ep/q; #energy of photon(eV)\n", "\n", "#Result\n", "print \"wavelength of beam of neutron is\",round(lamdan*10**10,3),\"angstrom\"\n", "print \"momentum of electron and photon is\",p,\"kgm/s\"\n", "print \"energy of electron is\",round(Ee,2),\"eV\"\n", "print \"energy of photon is\",round(Ep/10**3,2),\"*10**3 eV\"\n", "print \"answers in the book vary due to rounding off errors\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "wavelength of beam of neutron is 1.809 angstrom\n", "momentum of electron and photon is 3.66169359723e-24 kgm/s\n", "energy of electron is 46.04 eV\n", "energy of photon is 6.87 *10**3 eV\n", "answers in the book vary due to rounding off errors\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.4, Page number 260" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "e=1.6*10**-19; #charge of electron(C)\n", "V=200; #potential difference(V)\n", "lamda=0.0202*10**-10; #debroglie wavelength(m)\n", "h=6.625*10**-34; #planck's constant(Jsec)\n", "\n", "#Calculation\n", "#eV=0.5*m*(v^2)\n", "#mv=sqrt(2*m*eV)\n", "m=((h**2)/(2*(lamda**2)*e*V)); #mass of particle(kg)\n", "\n", "#Result\n", "print \"mass of particle is\",m,\"kg\"\n", "print \"hence it is a proton\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "mass of particle is 1.68069555834e-27 kg\n", "hence it is a proton\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.5, Page number 260" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration \n", "mn=1.676*10**-27; #mass of neutron(kg)\n", "e=1.6*10**-19; #charge of electron(C)\n", "h=6.622*10**-34; #planck's constant(Jsec)\n", "\n", "#Calculation\n", "E=e; #energy of neutron(J)\n", "v=math.sqrt((2*E)/mn); #velocity of neutron(m/sec)\n", "lamda=(h/(mn*v)); #de-broglie wavelength(m)\n", "\n", "#Result\n", "print \"de-broglie wavelength of neutron is\",round(lamda*10**10,3),\"angstrom\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "de-broglie wavelength of neutron is 0.286 angstrom\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 10.6, Page number 261" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration \n", "r=10**-14; #radius(m)\n", "h=6.625*10**-34; #planck's constant(Jsec)\n", "c=3*10**8; #velocity of light(m/s)\n", "mo=9.1*10**-31; #rest mass of particle(kg)\n", "q=1.6*10**-19; #charge of electron(C)\n", "\n", "\n", "#Calculation\n", "#acc. to uncertainity principle delx*delp >= (h/2*%pi)\n", "deltax=2*r; #uncertainity in position(m)\n", "deltap=(h/(2*math.pi*deltax)); ##uncertainity in momentum\n", "#from einstein's relavistic relation E=mc2=KE+rest mass energy=0.5mv2+moc2\n", "#when velocity of particle is very high\n", "#m=(mo/sqrt(1-((v/c)^2))) where m-mass of particle with velocity v,mo-rest mass of particle, c-velocity of particle\n", "p=deltap #assume\n", "E=math.sqrt(((p*c)**2)+((mo*(c**2))**2)); #energy(J)\n", "E=E/q; #energy(eV)\n", "\n", "#Result\n", "print \"energy is\",round(E/10**6),\"MeV\"\n", "print \"this value is much higher than experimentally obtained values of energy of electron of a radioactive nuclei i.e 4 Mev this proves that electron cannot reside within nucleus\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "energy is 10.0 MeV\n", "this value is much higher than experimentally obtained values of energy of electron of a radioactive nuclei i.e 4 Mev this proves that electron cannot reside within nucleus\n" ] } ], "prompt_number": 19 } ], "metadata": {} } ] }