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{
"metadata": {
"name": "",
"signature": "sha256:2419f2161da8f36d7fa10fabb5f5aa4b318a9912237faaa5f03ac922aa4b8ac9"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 10:Superconductivity"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.1 , Page no:313"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"Tc=7.2; #in K (critical temperature)\n",
"T=5; #in K (given temperature)\n",
"H0=6.5E3; #in A/m (critical magnetic field at 0K)\n",
"\n",
"#calculate\n",
"Hc=H0*(1-(T/Tc)**2); #calculation of magnitude of critical magnetic field\n",
"\n",
"#result\n",
"print\"The magnitude of critical magnetic field is Hc=\",round(Hc,2),\"A/m\";"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The magnitude of critical magnetic field is Hc= 3365.35 A/m\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.2 , Page no:313"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"r=0.02; #in m (radius of ring)\n",
"Hc=2E3; #in A/m (critical magnetic field at 5K)\n",
"pi=3.14; #value of pi used in the solutiion\n",
"\n",
"#calculate\n",
"Ic=2*pi*r*Hc; #calculation of critical current value\n",
"\n",
"#result\n",
"print\"The critical current value is Ic=\",Ic,\"A\";"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The critical current value is Ic= 251.2 A\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.3 , Page no:313"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"M1=199.5; #in amu (isotropic mass at 5K)\n",
"T1=5; #in K (first critical temperature)\n",
"T2=5.1; #in K (second critical temperature)\n",
"#calculate\n",
"#since Tc=C*(1/sqrt(M)\n",
"#therefore T1*sqrt(M1)=T2*sqrt(M2)\n",
"#therefore we have M2=(T1/T2)^2*M1\n",
"M2=(T1/T2)**2*M1; #calculation of isotropic mass at 5.1K\n",
"\n",
"#result\n",
"print\"The isotropic mass at 5.1K is M2=\",round(M2,3),\"a.m.u.\";"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The isotropic mass at 5.1K is M2= 191.753 a.m.u.\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.4 , Page no:314"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"T=6; #in K (given temperature)\n",
"Hc=5E3; #in A/m (critical magnetic field at 5K)\n",
"H0=2E4; #in A/m (critical magnetic field at 0K)\n",
"\n",
"#calculate\n",
"#since Hc=H0*(1-(T/Tc)^2)\n",
"#therefor we have Tc=T/sqrt(1-(Hc/H)^2)\n",
"Tc=T/math.sqrt(1-(Hc/H0)); #calculation of transition temperature\n",
"\n",
"#result\n",
"print\"The transition temperature is Tc=\",round(Tc,3),\"K\";\n",
"print \"NOTE: The answer in the textbook is wrong\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The transition temperature is Tc= 6.928 K\n",
"NOTE: The answer in the textbook is wrong\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.5 , Page no:314"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"T=5; #in K (given temperature)\n",
"d=3; #in mm (diameter of the wire)\n",
"Tc=8; #in K (critical temperature for Pb)\n",
"H0=5E4; #in A/m (critical magnetic field at 0K)\n",
"pi=3.14; #value of pi used in the solution\n",
"\n",
"#calculate\n",
"Hc=H0*(1-(T/Tc)**2); #calculation of critical magnetic field at 5K\n",
"r=(d*1E-3)/2; #calculation of radius in m\n",
"Ic=2*pi*r*Hc; #calculation of critical current at 5K\n",
"\n",
"#result\n",
"print\"The critical magnetic field at 5K is Hc=\",'%.3E'%Hc,\"A/m\";\n",
"print\"The critical current at 5K is Ic=\",round(Ic,4),\"A\";\n",
"print \" (roundoff error)\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The critical magnetic field at 5K is Hc= 3.047E+04 A/m\n",
"The critical current at 5K is Ic= 287.0156 A\n",
" (roundoff error)\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.6 , Page no:314"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"V=8.50; #in micro V (voltage across Josephson junction )\n",
"e=1.6E-19; #in C (charge of electron)\n",
"h=6.626E-34; #in J/s (Planck\u2019s constant)\n",
"\n",
"#calculate\n",
"V=V*1E-6; #changing unit from V to microVolt\n",
"v1=2*e*V/h; #calculation of frequency of EM waves\n",
"\n",
"#result\n",
"print\"The frequency of EM waves is v=\",'%.3E'%v1,\"Hz\";\n",
"print \"NOTE: The answer in the textbook is wrong\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The frequency of EM waves is v= 4.105E+09 Hz\n",
"NOTE: The answer in the textbook is wrong\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 10.7 , Page no:315"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"from __future__ import division\n",
"\n",
"#given\n",
"M1=200.59; #in amu (average atomic mass at 4.153K)\n",
"Tc1=4.153; #in K (first critical temperature)\n",
"M2=204; #in amu (average atomic mass of isotopes)\n",
"\n",
"#calculate\n",
"#since Tc=C*(1/sqrt(M)\n",
"#therefore T1*sqrt(M1)=T2*sqrt(M2)\n",
"#therefore we have Tc2=Tc1*sqrt(M1/M2)\n",
"Tc2=Tc1*math.sqrt(M1/M2); #calculation of transition temperature of the isotopes\n",
"\n",
"#result\n",
"print\"The transition temperature of the isotopes is Tc2=\",round(Tc2,3),\"K\";"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The transition temperature of the isotopes is Tc2= 4.118 K\n"
]
}
],
"prompt_number": 7
}
],
"metadata": {}
}
]
}
|
