{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 10: Electromagnetism" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.15, Page 10.42" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given \n", "n = 2000 # flux lines enter in given volume in Vm\n", "n_ = 4000 # flux lines diverge from given volume in Vm\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculations\n", "fi = n_ - n\n", "q = e0 * fi\n", "\n", "#Result\n", "print 'The total charge within volume(in C) = ',q" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The total charge within volume(in C) = 1.77e-08\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.16, Page 10.42" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given \n", "n = 20000 # flux lines entering in given volume in Vm\n", "n_ = 45000 # flux lines entering out from given volume in Vm\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculations\n", "fi = n_ - n\n", "q = e0 * fi\n", "\n", "#Result\n", "print \"The total charge enclosed by closed surface is %.3e C\"%q" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The total charge enclosed by closed surface is 2.212e-07 C\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.17, Page 10.43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given \n", "q = 13.5e-6 # charge enclosed at the centre of cube in C\n", "l = 6 # length of the side of cube in cm\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculations\n", "fi = q / e0\n", "fi_ = fi / 6\n", "q = e0 * fi\n", "\n", "#Results\n", "print \"Electric flux through the whole volume of the cube is %.3e Nm^2/C\\nElectric flux through one face of the cube is %.2e Nm^2/C\"%(fi,fi_)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Electric flux through the whole volume of the cube is 1.525e+06 Nm^2/C\n", "Electric flux through one face of the cube is 2.54e+05 Nm^2/C\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.18, Page 10.43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given \n", "q = 11 # charge enclosed at the centre of cube in C\n", "l = 5 # length of the side of cube in cm\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculation\n", "fi_ = (q / e0) / 6\n", "\n", "#Result\n", "print \" Electric flux through each surface of the cube = %.2e Nm^2/C\"%fi_" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Electric flux through each surface of the cube = 2.07e+11 Nm^2/C\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.19, Page 10.43" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "q = 1e-8 # charge uniformly spread over metallic sphere in C\n", "r = .1 #radius of sphere in m\n", "d = 7 # distance of a point from centre of the sphere in cm\n", "d_ = .5 # distance of another point from centre of the sphere in m\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#calculations\n", "E1 = (1 / (4 * pi * e0) * (q / r**2))\n", "E2 = 0 #because sphere is metallic\n", "E3 = (1 / (4 * pi * e0) * (q / d_**2))\n", "\n", "#Result\n", "print \"Electric field intensity-\\n(1) On the surface of the sphere = %.e N/C\\n(2) At first point = %d N/C\\n(3)At second point = %.2e N/C\"%(E1,E2,E3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Electric field intensity-\n", "(1) On the surface of the sphere = 9e+03 N/C\n", "(2) At first point = 0 N/C\n", "(3)At second point = 3.60e+02 N/C\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.20, Page 10.44" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "q = 1.6e-19 # charge on a proton in C\n", "d = 1e-10 # distance of a point from proton in m\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculation\n", "E = (1 / (4 * pi * e0)) * (q / d**2)\n", "\n", "#Result\n", "print \"Electric field = %.2e V/m\"%E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Electric field = 1.44e+11 V/m\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.21, Page 10.44" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given \n", "v = 1000 # potential through which alpha particle accelerated in V\n", "q = 3.2e-19 # charge on an alpha particle in C\n", "e0 = 8.85e-12 # electric permittivity of space\n", "\n", "#calculation\n", "E = q * v\n", "\n", "#Result\n", "print \"Energy gained by alpha particle = %.1e J\"%E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy gained by alpha particle = 3.2e-16 J\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.22, Page 10.44" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "q = 1.6e-19 # charge on a proton in C\n", "d = 1e-10 # distance of a point from proton in m\n", "d_ = 2e-11 # distance of another point from proton in m\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#calculations\n", "v = (1 / (4 * pi * e0)) * (q / d)#calculation for potential at first point\n", "E = -q * v#calculation for energy at first point in J\n", "delta_v = (1 / (4 * pi * e0)) * q * ((1 / d_) - (1 / d))#calculation for potential difference between points\n", "\n", "#Result\n", "print \"Potential energy at first point = %.1f eV\\nPotential difference between points = %.1f V\"%(E/q,delta_v)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Potential energy at first point = -14.4 eV\n", "Potential difference between points = 57.5 V\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.23, Page 10.45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi, ceil\n", "\n", "# Given \n", "q = 1.5e-6 # charge in C\n", "v = 30 # potential of a surface in V\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculation\n", "r = (1 / (4 * pi * e0)) * (q / v)\n", "\n", "#Result\n", "print \"Radius of equipotential surface = %d m\"%ceil(r)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radius of equipotential surface = 450 m\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.24, Page 10.45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "p = 3.8e26 # power radiated by sun in W\n", "r = 7e8 # radius of sun in m\n", "e0 = 8.85e-12 # permittivity of space\n", "\n", "#Calculation\n", "s = p / (4 * pi * r**2)\n", "\n", "#Result\n", "print \"The value of poynting vector at the surface of the sun = %.3e W/m^2\"%s" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of poynting vector at the surface of the sun = 6.171e+07 W/m^2\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.25, Page 10.45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "Se = (2*4.2)/(60*10**-4) #J/m^2-sec\n", "c = 3*10**8 #m/s\n", "res = 1.4*10**11 #m\n", "rs = 7*10**7 #W/m^2\n", "\n", "#Calculations\n", "Prad_e = Se/c\n", "Ss = Se*((res/rs)**2)\n", "Prad_s = Ss/c\n", "\n", "#Results\n", "print \"Radiation pressure at the surface of the earth =%.2e N/m^2\"%Prad_e\n", "print \"Radiation pressure at the surface of the sun =%.3e N/m^2\"%Prad_s" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radiation pressure at the surface of the earth =4.67e-06 N/m^2\n", "Radiation pressure at the surface of the sun =1.867e+01 N/m^2\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.28, Page 10.47" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt\n", "\n", "# Given \n", "s = 2 # energy received by the earth in cal/cm^2.min\n", "e0 = 8.85e-12 # electric permittivity of space\n", "mu0 = 1.2567e-6 # magnetic permittivity of space\n", "c = 3e8 # speed of light in meter/sec\n", "\n", "#calculations\n", "r = sqrt(mu0 / e0)\n", "P = s*4.2/(60*1e-4)\n", "E = sqrt(P*r)\n", "H = E/r\n", "\n", "#Result\n", "print \"Magnitude of electric field vector = %.1f v/m\\nMagnitude of magnetic field vector = %.3f A/m\"%(E * sqrt(2),H*sqrt(2))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Magnitude of electric field vector = 1027.2 v/m\n", "Magnitude of magnetic field vector = 2.726 A/m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.29, Page 10.48" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt\n", "\n", "# Given \n", "H = 1 # magnitude of magnetic field vector A/m\n", "e0 = 8.85e-12 # electric permittivity of space\n", "mu0 = 1.2567e-6 # magnetic permittivity of space\n", "c = 3e8 # speed of light in meter/sec\n", "\n", "#Calculations\n", "r = sqrt(mu0 / e0) # ratio of E,H\n", "E = H * r\n", "\n", "#Result\n", "print \"Magnitude of electric field vector = %.2f v/m.\"%E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Magnitude of electric field vector = 376.83 v/m.\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.31, Page 10.48" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "\n", "# Given \n", "p = 1000 # power of lamp in W\n", "d = 2 # distance of a point from lamp in meter\n", "e0 = 8.85e-12 # electric permittivity of space\n", "mu0 = 1.2567e-6 # magnetic permittivity of space\n", "c = 3e8 # speed of light in meter/sec\n", "\n", "#Calculations\n", "s = p / (4 * pi * d**2) #calculation for \n", "r = sqrt(mu0 / e0) # ratio of E,H\n", "E = sqrt(s * r)#calculation for average value of intensity of electric field of radiation\n", "\n", "#Result\n", "print \"Average value of the intensity of electric field of radiation = %.2f v/m.\"%E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Average value of the intensity of electric field of radiation = 86.58 v/m.\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.32, Page 10.49" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt\n", "\n", "# Given \n", "k = 81 # relative permittivity of water \n", "c = 3e8 # speed of light in meter/sec\n", "\n", "#Calculations\n", "mu = sqrt(k)\n", "v = c / mu\n", "\n", "#Result\n", "print \"Refractive index of distilled water is %d \\nSpeed of light in water is %.2e m/sec\"%(mu,v)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Refractive index of distilled water is 9 \n", "Speed of light in water is 3.33e+07 m/sec\n" ] } ], "prompt_number": 5 } ], "metadata": {} } ] }