{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Capter 19: Magnetic Materials" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.1, page no-541" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Relative permiability and magnetic force\n", "\n", "import math\n", "#Variable Declaration\n", "M=2300.0 # Magnetization\n", "B=0.00314 # Flux density\n", "\n", "#Calculation\n", "mu=4*math.pi*10**-7\n", "H=(B/mu)-M\n", "mur=(M/H)+1\n", "\n", "#Result\n", "print('The magnetic force H is %.4f A/m and the relative permeability mu_r is %.5f'%(H,mur))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnetic force H is 198.7326 A/m and the relative permeability mu_r is 12.57334\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.2, page no-542" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# magnetisation and flux density\n", "\n", "import math\n", "#Variable Declaration\n", "H=10**4 # Magnetic field intensity\n", "sus=3.7*10**-3 # Susceptibility\n", "mu=4*math.pi*10**-7 # permeability of free space\n", "\n", "#Calculation\n", "M=sus*H\n", "B=mu*(M+H)\n", "\n", "#Result\n", "print('The magnetisation in the material is %.0f A/m and flux density in the material is %.2f * 10^-2 Wb.m^-2'%(M,B*10**2))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnetisation in the material is 37 A/m and flux density in the material is 1.26 * 10^-2 Wb.m^-2\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.3, page no-542" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Flux density in a material\n", "\n", "import math\n", "#variable declaration\n", "H=10**4 # Magnetic field intensity \n", "sus=-0.8*10**-5 # susceptibility of copper\n", "mu=4*math.pi*10**-7 # permeability of free space\n", "\n", "#Calculations\n", "M=sus*H\n", "B=mu*(M+H)\n", "\n", "#Result\n", "print('The flux density in the material is %.2f * 10^-2 Wb.m^-2'%(B*10**2))\n", "\n", "# Magnetic field intensity: value given in the book is 10^6 but calculations are done with 10^4" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The flux density in the material is 1.26 * 10^-2 Wb.m^-2\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.4, page no-543" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Permeability \n", "\n", "import math\n", "# Variable declarations\n", "H=1800.0 # Magnetic field intensity\n", "fi=3*10**-5 # Magnetic flux\n", "A=0.2*10**-4 # Area of cross-section \n", "\n", "#Calculations\n", "B=fi/A\n", "mu=B/H\n", "\n", "#Result\n", "print('\\nThe magnetic flux is %.1f Wb/m^2\\nThe permeability is %.3f*10^-4 H/m'%(B,mu*10**4))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "The magnetic flux is 1.5 Wb/m^2\n", "The permeability is 8.333*10^-4 H/m\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.5, page no-544" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Magnetic moment of Nickel\n", "\n", "import math\n", "#variable declaration\n", "B=0.65 # Magnetic inductionof Nickel\n", "r=8906 # Density of Nickel\n", "M=58.7 # Atomic weight\n", "avg=6.023*10**26 # Avogadro's Number\n", "mu=4*math.pi*10**-7 # Permeability of free space\n", "k=9.27*10**-24 # 1 Bohr Magnetron\n", "\n", "#Calculations\n", "N=r*avg/M \n", "mu_m=B/(N*mu)\n", "mu_m=mu_m/k\n", "\n", "#Result\n", "print(\"The magnetic moment of nickel atom is %.2f Bohr magneton\"%mu_m)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnetic moment of nickel atom is 0.61 Bohr magneton\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.6, page no-545" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Average magnetization contributed per atom\n", "\n", "import math\n", "# Variable declaration\n", "a=2.5*10**-10 # interatomic spacing\n", "M=1.8*10**6 # MAgnetization\n", "e=1.6*10**-19 # charge of an electron\n", "\n", "#Calculations\n", "n=2/a**3\n", "m=9.1*10**-31\n", "h=6.625*10**-34\n", "ma=M/n\n", "beta1=e*h/(4*math.pi*m)\n", "\n", "#Result\n", "print(\"The average magnetisation contributed per atom = %.3f Bohr Magneton\"%(ma/beta1))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The average magnetisation contributed per atom = 1.517 Bohr Magneton\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.7, page no-545" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Tempoerature using classical statistics\n", "\n", "import math\n", "#Variable declarations\n", "mu=9.4*10**-24 # Permeability \n", "H=2 # MAgnetic field intensity\n", "k=1.38*10**-23 # Bolzmann's constant\n", "\n", "#Calculations\n", "T=2*mu*H/(k*math.log(2))\n", "\n", "#Result\n", "print(\"The temperature of the system T is %.1f K\"%T)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The temperature of the system T is 3.9 K\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.8, page no-547" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Saturation magnetic field of Gd atom\n", "\n", "import math\n", "#Variable declaration\n", "ba=7.1 # Bohr magnetron per atom\n", "aw=1.8*10**6 # Atomic weight of Gd \n", "d=7.8*10**3 # Density of Gd\n", "avg=6.023*10**26 # Avogadro's Number\n", "M=157.26 # Atomic number of Gd\n", "k=9.27*10**-24 # 1 Bohr magnetron\n", "mu=4*math.pi*10**-7 # permeability of free space\n", "\n", "\n", "#Calculations\n", "N=d*avg/M\n", "mm=N*ba*k\n", "B=N*mu*k*7.1\n", "\n", "#Result\n", "print(\"\\nThe saturation magnetic field of Gd atom is %.2f Wb/m^2\"%B)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "The saturation magnetic field of Gd atom is 2.47 Wb/m^2\n" ] } ], "prompt_number": 48 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.9, page no-547" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#saturation magnetisation\n", "\n", "import math\n", "# variable ddeclaration\n", "bet=9.27*10**-24 # 1 Bohr magnetron\n", "V=0.839*10**-9 # unit cell edge length\n", "\n", "#Calculations\n", "M=32*bet/V**3\n", "\n", "#Result\n", "print(\"The saturation magnetisation is %.3f *10^5 A/m\"%(M*10**-5))\n", "# Answer in the book is given as 5.023 x 10^-5" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The saturation magnetisation is 5.023 *10^5 A/m\n" ] } ], "prompt_number": 55 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.10, page no-548" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Saturation flux density\n", "\n", "import math\n", "#variable declaration\n", "d=8900 # Density of Ni\n", "wt=58.71 # Atomic weight\n", "avg=6.022*10**26 # Avogadro's Number\n", "bet=9.27*10**-24 # 1 Bohr magnetron\n", "mu=4*math.pi*10**-7 # permeability of free space\n", "\n", "#Calculations\n", "mm=0.6*bet\n", "N=d*avg/wt\n", "ms=mm*N\n", "bs=mu*ms\n", "\n", "#Result\n", "print(\"\\nThe saturation magnetisation is %.3f *10^5 A/m\\nThe saturation flux density is %.3f Wb/m^2\"%(ms*10**-5,bs))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "The saturation magnetisation is 5.077 *10^5 A/m\n", "The saturation flux density is 0.638 Wb/m^2\n" ] } ], "prompt_number": 57 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.11, page no-548" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Saturation magnetisation of gadolinium\n", "\n", "import math\n", "#variable declaration\n", "awt=157.25 # Atomic weight\n", "an=64 # Atomic number\n", "d=7860 # density\n", "k=9.27*10**-24 # 1 Bohr magnetron\n", "avg=6.023*10**26 # avogadro's Number\n", "\n", "#Calculations\n", "N=d*8*k*avg/awt\n", "\n", "# Result\n", "print(\"The saturation magnetisation of gadolinium is %.2f*10^6 A/m\"%(N*10**-6))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The saturation magnetisation of gadolinium is 2.23*10^6 A/m\n" ] } ], "prompt_number": 58 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 19.12, page no-549" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Magnetic flux density inside the material\n", "\n", "import math\n", "#variable declaration\n", "H=1000 # Magnetic field strength\n", "sus=-0.3*10**-5 # magnetic susceptibility\n", "mu=4*math.pi*10**-7 # permeability of free space\n", "\n", "#calculation\n", "M=sus*H\n", "B=mu*(M+H)\n", "B=math.floor(B*10**6)/10**6\n", "\n", "#Result\n", "print(\"The magnetic flux density inside the material is %.3f T or Wb.m^-2\"%(B*10**3))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnetic flux density inside the material is 1.256 T or Wb.m^-2\n" ] } ], "prompt_number": 67 } ], "metadata": {} } ] }