{
"metadata": {
"name": "",
"signature": "sha256:f048d58df41f2578c151ef59f03652004b6758b9e666d170255be2c66115bfe2"
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"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"2: Particle nature of radiation"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.1, Page number 28"
]
},
{
"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; #planck's constant(Js)\n",
"new=100*10**6; #frequency(Hz)\n",
"P=100*10**3; #power(watt)\n",
"\n",
"#Calculation\n",
"E=h*new; #quantum of energy(J)\n",
"n=P/E; #number of quanta emitted(per sec)\n",
"\n",
"#Result\n",
"print \"number of quanta emitted is\",round(n/10**29,2),\"*10**29 per sec\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"number of quanta emitted is 15.09 *10**29 per sec\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.2, Page number 31"
]
},
{
"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; #planck's constant(Js)\n",
"c=3*10**8; #velocity of light(m/sec)\n",
"lamda=400*10**-9; #wavelength(m)\n",
"e=1.6*10**-19; #conversion factor from J to eV\n",
"w0=2.28; #work function(eV)\n",
"m=9.1*10**-31; #mass of electron(kg)\n",
"\n",
"#Calculation\n",
"E=h*c/(lamda*e); #energy(eV)\n",
"KEmax=E-w0; #maximum kinetic energy(eV)\n",
"v2=2*KEmax*e/m; \n",
"v=math.sqrt(v2); #velocity(m/s)\n",
"\n",
"#Result\n",
"print \"maximum kinetic energy is\",round(KEmax,3),\"eV\"\n",
"print \"velocity of photoelectrons is\",round(v/10**5,2),\"*10**5 m/s\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"maximum kinetic energy is 0.826 eV\n",
"velocity of photoelectrons is 5.39 *10**5 m/s\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.3, Page number 31"
]
},
{
"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; #planck's constant(Js)\n",
"c=3*10**8; #velocity of light(m/sec)\n",
"lamda=2000*10**-10; #wavelength(m)\n",
"e=1.6*10**-19; #conversion factor from J to eV\n",
"w0=4.2; #work function(eV)\n",
"\n",
"#Calculation\n",
"lamda0=h*c/(w0*e); #cut off wavelength(m)\n",
"E=h*c/(lamda*e); #energy(eV)\n",
"sp=E-w0; #stopping potential(eV)\n",
"\n",
"#Result\n",
"print \"cut off wavelength is\",int(lamda0*10**10),\"angstrom\"\n",
"print \"stopping potential is\",round(sp,2),\"V\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"cut off wavelength is 2958 angstrom\n",
"stopping potential is 2.01 V\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.4, Page number 33"
]
},
{
"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; #planck's constant(Js)\n",
"c=3*10**8; #velocity of light(m/sec)\n",
"lamda=0.2*10**-9; #wavelength(m)\n",
"\n",
"#Calculation\n",
"p=h/lamda; #momentum(kg m/s)\n",
"m=p/c; #effective mass(kg)\n",
"\n",
"#Result\n",
"print \"momentum is\",round(p*10**24,1),\"*10**-24 kg m/s\"\n",
"print \"effective mass is\",round(m*10**32,1),\"*10**-32 kg\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"momentum is 3.3 *10**-24 kg m/s\n",
"effective mass is 1.1 *10**-32 kg\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.5, Page number 35"
]
},
{
"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; #planck's constant(Js)\n",
"c=3*10**8; #velocity of light(m/sec)\n",
"lamda=0.15; #wavelength(nm)\n",
"m0=9.1*10**-31; #mass of electron(kg)\n",
"theta1=0; #scattering angle1(degrees)\n",
"theta2=90; #scattering angle2(degrees)\n",
"theta3=180; #scattering angle3(degrees)\n",
"\n",
"#Calculation\n",
"theta1=theta1*math.pi/180; #scattering angle1(radian)\n",
"theta2=theta2*math.pi/180; #scattering angle2(radian)\n",
"theta3=theta3*math.pi/180; #scattering angle3(radian)\n",
"lamda_dash1=lamda+(h*(1-math.cos(theta1))/(m0*c)); #wavelength at 0(nm)\n",
"lamda_dash2=lamda+(10**9*h*(1-math.cos(theta2))/(m0*c)); #wavelength at 90(nm)\n",
"lamda_dash3=lamda+(10**9*h*(1-math.cos(theta3))/(m0*c)); #wavelength at 180(nm)\n",
"\n",
"#Result\n",
"print \"wavelength at 0 degrees is\",lamda_dash1,\"nm\"\n",
"print \"wavelength at 90 degrees is\",round(lamda_dash2,3),\"nm\"\n",
"print \"wavelength at 180 degrees is\",round(lamda_dash3,3),\"nm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"wavelength at 0 degrees is 0.15 nm\n",
"wavelength at 90 degrees is 0.152 nm\n",
"wavelength at 180 degrees is 0.155 nm\n"
]
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example number 2.6, Page number 36"
]
},
{
"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; #planck's constant(Js)\n",
"c=3*10**8; #velocity of light(m/sec)\n",
"e=1.6*10**-19; #conversion factor from J to eV\n",
"E=2*0.511*10**6; #rest energy(eV)\n",
"\n",
"#Calculation\n",
"lamda=h*c/(E*e); #wavelength of photon(m)\n",
"\n",
"#Result\n",
"print \"wavelength of photon is\",round(lamda*10**12,2),\"*10**-12 m\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"wavelength of photon is 1.22 *10**-12 m\n"
]
}
],
"prompt_number": 21
}
],
"metadata": {}
}
]
}