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  {

   "cells": [

    {

     "cell_type": "heading",

     "level": 1,

     "metadata": {},

     "source": [

      "Chapter18:Magnetic Materials"

     ]

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.1:pg-346"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.1 : magnetization and flux density\n",

      "import math\n",

      "#given data :\n",

      "mu0=4*math.pi*10**-7;\n",

      "H=10**4;# in A/m\n",

      "Xm=3.7*10**-3;# room temperature\n",

      "mu_r=1+Xm;\n",

      "B=mu0*mu_r*H;\n",

      "M=Xm*H;\n",

      "print B,\"= the flux density,B(Wb/m**2) \"\n",

      "print M,\"= magnetization,M(A/m) \"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "0.0126128661856 = the flux density,B(Wb/m**2) \n",

        "37.0 = magnetization,M(A/m) \n"

       ]

      }

     ],

     "prompt_number": 1

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.2a:pg-350"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.2.a : saturation magnetization\n",

      " \n",

      "#given data :\n",

      "mu_b=9.27*10**-24;# A.m**2\n",

      "p=8.9; # in g/cm**3\n",

      "Na=6.023*10**23;# avogadro's number\n",

      "A=58.71; # in g/mol\n",

      "n=((p*Na)/A)*10**6;\n",

      "Ms=0.60*mu_b*n;\n",

      "print Ms,\"= saturation magnetization,Ms(A/m) \"\n",

      "# the answe ris slightly different in textbook due to approximation"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "507834.0 = saturation magnetization,Ms(A/m) \n"

       ]

      }

     ],

     "prompt_number": 2

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.2b:pg-350"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.2.b : saturation flux density\n",

      "import math\n",

      "#given data :\n",

      "\n",

      "mu0=4*math.pi*10**-7;\n",

      "mu_b=9.27*10**-24;# A.m**2\n",

      "p=8.9; # in g/cm**3\n",

      "Na=6.023*10**23;# avogadro's number\n",

      "A=58.71; # in g/mol\n",

      "n=((p*Na)/A)*10**6;\n",

      "Ms=0.60*mu_b*n;\n",

      "Bs=mu0*Ms;\n",

      "print round(Bs,2),\"= saturation flux density,Bs(tesla) \"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "0.64 = saturation flux density,Bs(tesla) \n"

       ]

      }

     ],

     "prompt_number": 4

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.3:pg-351"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.3 : magnetic moment\n",

      "import math \n",

      "#given data :\n",

      "\n",

      "mu0=4*math.pi*10**-7;\n",

      "mu_b=9.27*10**-24;# A.m**2\n",

      "p=8.9; # in g/cm**3\n",

      "Na=6.023*10**23;# avogadro's number\n",

      "A=58.71; # in g/mol\n",

      "n=((p*Na)/A)*10**6;\n",

      "Bs=0.65;#in Wb/m**2\n",

      "Ms=Bs/mu0;\n",

      "m_mu_b=Ms/n;\n",

      "print round(m_mu_b,26),\" is saturation magnetisation,m_mu_b(A.m**2) \"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "5.67e-24  is saturation magnetisation,m_mu_b(A.m**2) \n"

       ]

      }

     ],

     "prompt_number": 11

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.4:pg-355"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.4 : power loss\n",

      " \n",

      "#given data :\n",

      "V=0.01;#in m**3\n",

      "f=50;# in Hz\n",

      "area=600;#in jm**-1\n",

      "Wh=area*V*f;\n",

      "print Wh,\"= power loss,Wh(watts) \"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "300.0 = power loss,Wh(watts) \n"

       ]

      }

     ],

     "prompt_number": 12

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex18.5:pg-355"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Example 18.4 : los of energy\n",

      " \n",

      "#given data :\n",

      "mass=10.0;# in kg\n",

      "energy_loss=250.0;# in J/m**2\n",

      "#energy loss at the rate of 50 cycles/s\n",

      "E=energy_loss*50.0;# in J/m**3\n",

      "E_loss=E*3600.0;#in J/m**3\n",

      "D=7500.0;#density in kg/m**3\n",

      "Volume=mass/D;\n",

      "energy_loss_per_hour=E_loss/Volume;\n",

      "print energy_loss_per_hour,\"= energy_loss_per_hour(J/hour) \"\n",

      "\n",

      "# answer is incorrect in textbook"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "33750000000.0 = energy_loss_per_hour(J/hour) \n"

       ]

      }

     ],

     "prompt_number": 22

    }

   ],

   "metadata": {}

  }

 ]

}