{ "metadata": { "name": "", "signature": "sha256:9ccabd1c0a5d5861a1e63defe760a8b9caed49864d9aebb3ab3b0741ed755b61" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7: Dielectric Properties" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.1, Page number 7.23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "C = 2*10**-6 #Capacitance(F)\n", "V = 1000 #voltage(V)\n", "Er = 100 #permittivity\n", "\n", "#Calculations\n", "W = (C*V**2)/2\n", "\n", "Co = C/Er\n", "Wo = (Co*V**2)/2\n", "Wf = W-Wo\n", "\n", "#Result\n", "print \"Energy stored in condenser =\",W,\"J\"\n", "print \"Energy stored in polarizing the dilectric =\",Wf,\"J\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy stored in condenser = 1.0 J\n", "Energy stored in polarizing the dilectric = 0.99 J\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.2, Page number 7.24" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaraion\n", "Er = 4.94 #permittivity\n", "n2 = 2.69 #index of refraction\n", "\n", "#Calculations\n", "'''\n", "Er - 1 N(ae+ai)\n", "------ = ---------\n", "Er + 2 3*Eo \n", "Sunbstituting the values for Er, we get,\n", "N(ae+ai) \n", "-------- = 0.5677 ------------(1)\n", " 3*ao\n", "'''\n", "x = 0.5677\n", "\n", "'''\n", "Also, Er = n**2\n", "Therefore, n**2-1 N*ae\n", " ------- = -----\n", " n**2+2 3*Eo\n", "Substituting the values for n^2, we get,\n", "N*ae\n", "---- = 0.36034 ---------------(2)\n", "3*Eo\n", "'''\n", "y = 0.36034\n", "#Let z = ai/ae\n", "#Dividing equation (1) by (2), we get,\n", "\n", "z = (x/y)-1\n", "\n", "#Result\n", "print \"Ratio between electronic and ionic probabbility is\",round(z,3) ,\"or\",round((1/z),3)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio between electronic and ionic probabbility is 0.575 or 1.738\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.3, Page number 7.25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Variable declaration\n", "Er = 2.56 #permittivity\n", "f = 1*10**6 #frequency(Hz)\n", "A = 8*10**-4 #area(m^2)\n", "d= 0.08*10**-3 #distance of seperation(m)\n", "Eo = 8.85*10**-12\n", "\n", "#Calculations\n", "Er_dash = Er*0.7*10**-4\n", "w = 2*math.pi*f\n", "Rp = d/(w*Eo*Er_dash*A)\n", "\n", "Cp = (A*Eo*Er)/d\n", "\n", "#Results\n", "print \"Parallel loss resistance =\",round((Rp/1E+6),2),\"MOhms\"\n", "print \"Capacitance =\",Cp,\"F(Calculation mistake in textbook)\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Parallel loss resistance = 10.04 MOhms\n", "Capacitance = 2.2656e-10 F(Calculation mistake in textbook)\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.5, Page number 7.26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Varaible declaration\n", "N = 3.*10**28 #density(atoms/m^3)\n", "ae = 10.**-40 #electronic polarizability(F m^2)\n", "Eo = 8.854*10**-12 #permittivity of free space(F/m)\n", "\n", "#Calculaion\n", "Er = 1+((N*ae)/Eo)\n", "\n", "#Result\n", "print \"dielectric constant =\",round(Er,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "dielectric constant = 1.339\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.5, Page number 7.26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "Er = 1.0000684 #permittivity of dilectric\n", "Eo = 8.854*10**-12 #permittivity of free space(F/m)\n", "N = 2.7*10**25 #density(atoms/m^3)\n", "\n", "#Calculation\n", "ae = (Eo*(Er-1))/N\n", "\n", "#Result\n", "print \"Electronic polarizability =\",round((ae/1E-41),3),\"*10^-41 Fm^2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Electronic polarizability = 2.243 *10^-41 Fm^2\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.6, Page number 7.27" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "A = 100*10**-4 #area of parallel capacitor(m^2)\n", "d = 1*10**-2 #separation between plates(m)\n", "Eo = 8.854*10**-12 #permittivity of free space(F/m)\n", "V = 100 #voltage(V)\n", "\n", "#Calculation\n", "C = (Eo*A)/d\n", "Q = C*V\n", "\n", "#Result\n", "print \"Capacitance =\",round((C/1E-12),2),\"pF\"\n", "print \"Charge =\",Q,\"C\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Capacitance = 8.85 pF\n", "Charge = 8.854e-10 C\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.7, Page number 7.28" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "N = 6.02*10**26 #Avogadro's number\n", "den = 2050 #density(kg/m^3)\n", "Ma = 32 #atomic weight\n", "Eo = 8.55*10**-12 #permittivity of free space(F/m)\n", "v = 1/3 #internal field constant\n", "Er = 3.75 #dielectric constant of sulphur\n", "\n", "#Calculations\n", "n = (N*den)/Ma #no. of atoms per m^3\n", "ae = ((Er-1)/(Er+2))*((3*Eo)/n)\n", "\n", "#Result\n", "print \"Electronic polarizability =\",round((ae/1E-40),3),\"*10^-41 Fm^2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Electronic polarizability = 3.181 *10^-41 Fm^2\n" ] } ], "prompt_number": 11 } ], "metadata": {} } ] }