{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 13: Magnetic Materials" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.1, Page 457" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "#Variable declaration\n", "u0=4*pi*1e-7;\n", "H=1e7;#magnetic field strength\n", "X=(-0.9)*1e-6;#magnetic suseptiblity\n", "\n", "#Calculations&Results\n", "M=X*H;#magnetization of material\n", "print 'magnetization of material is %.f A/m'%M\n", "B=u0*H;#magnetic flux density\n", "print 'magnetic flux density is %.2f Wb/m^2'%B\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "magnetization of material is -9 A/m\n", "magnetic flux density is 12.57 Wb/m^2\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.2, Page 457" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "#Variable declaration\n", "X=2*1e-3;#magnetic suseptibility of material at room temp.\n", "H=1e3;#magnetic field intrnsity of piece of ferricoxide\n", "u0=4*pi*1e-7;\n", "\n", "#Calculatons&Results\n", "M=X*H;#magnetization\n", "print 'magnetization is %.f A/m'%M\n", "ur=X+1;#relative permiability\n", "B=u0*ur*H;#magnetic flux density\n", "print 'magnetic flux density is %.3f*10^-3 W/m^2'%(B/1e-3)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "magnetization is 2 A/m\n", "magnetic flux density is 1.259*10^-3 W/m^2\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.3, Page 458" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "M=2.74*1e8;#magnetization per atom in A/m\n", "a=2.66*1e-10;#elementry cube edge\n", "n=2;#Iron in BCC\n", "\n", "#Calculations&Results\n", "B=(M*a**3)/2;#Am^2 per atom\n", "print 'Average number of Bohr magnetons contributed are %.2f*10^-22'%(B/1e-22)\n", "#interms of bohr megneton\n", "b=B/(9.27*1e-24);#dipole moment\n", "print 'dipole moment is %.f bohr megneton/atom'%b\n", "#Incorrect answers in the textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Average number of Bohr magnetons contributed are 25.78*10^-22\n", "dipole moment is 278 bohr megneton/atom\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.4, Page 258" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "#Variable declaration\n", "u0=4*pi*1e-7;\n", "b=9.27*1e-24;\n", "H=1e3;#homogeneous field\n", "k=1.38*1e-23;#boltzmann constant\n", "T=303;#temp in kelvin\n", "\n", "#Calculations\n", "T1 = T - 273; # Temp In Degree\n", "x=u0*b*H/(k*T);#avg magnetic moment\n", "\n", "#Result\n", "print 'avg magnetic moment is %.2f*10^-6 bohr magneton/spin'%(x/1e-6)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "avg magnetic moment is 2.79*10^-6 bohr magneton/spin\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.5, Page 459" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable declaration\n", "ur=16;#relative permiability\n", "I=3300;#intensity of magnetization\n", "\n", "#Calculation\n", "H=I/(ur-1);#strength of the field\n", "\n", "#Result\n", "print 'strength of the field =%.f A/m'%H\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "strength of the field =220 A/m\n" ] } ], "prompt_number": 5 } ], "metadata": {} } ] }