{ "metadata": { "name": "", "signature": "sha256:07eafc200928a1fc85942d637323ac709731a49898cf69ec16ea9de55515ee47" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 7: Magnetostatic Fields

" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.1, Page number: 266

" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "import scipy\n", "\n", "#Variable Declaration\n", "\n", "p=5 #Distance from side 1 of loop to (0,0,5) in m\n", "l=2 #Length of the side in m\n", "I=10 #Current through loop in A\n", "\n", "#Calculation\n", "\n", "a1=scipy.arccos(l/(scipy.sqrt(l**2+p**2))) #Angle in radians\n", "a2=scipy.pi/2 #Angle in radians\n", "H=I*(scipy.cos(a1)-scipy.cos(a2))/(4*scipy.pi*p) #Field Intensity in A/m\n", "\n", "#Result\n", "\n", "print 'H=',round(H*1000,1),'mA/m in the negative y direction'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "H= 59.1 mA/m in the negative y direction\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.2, Page number: 268

" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "import scipy\n", "from numpy import *\n", "\n", "#Variable Declaration\n", "\n", "ax=array([1,0,0]) #Unit vector along x direction\n", "ay=array([0,1,0]) #Unit vector along y direction\n", "az=array([0,0,1]) #Unit vector along z direction\n", "a1=scipy.arccos(0)\n", "a2=scipy.arccos(1)\n", "b1=scipy.arccos(0.6)\n", "b2=scipy.arccos(1)\n", "p1=5\n", "p2=4\n", "I1=3 #current in A\n", "I2=3 #current in A\n", "\n", "#Calculations\n", "\n", "Hz=I1/(4*scipy.pi*p1)*(cos(a2)-cos(a1))*array([0.8,0.6,0])\n", "Hx=I2/(4*scipy.pi*p2)*(cos(b2)-cos(b1))*array([0,0,1])\n", "Hzcyl=-I1/(4*scipy.pi*p1)*array([0,1,0])\n", "Hzx=round(dot(Hz,ax),4)\n", "Hzy=round(dot(Hz,ay),5)\n", "Hxz=round(dot(Hx,az),5)\n", "Hxr=array([0,0,Hxz])\n", "Hzr=array([Hzx,Hzy,0])\n", "Hzcyly=round(dot(Hzcyl,ay),5)\n", "Hzcylr=array([0,Hzcyly,0])\n", "Hcart=(Hxr+Hzr)*10**3 #H in cartesian coordinates in mA \n", "Hcyl=(Hxr+Hzcylr)*10**3 #H in cylindrical coordinates in mA\n", "\n", "#Result\n", "\n", "print 'H at (-3, 4, 0) in cartesian coordnates =',Hcart,'mA/m'\n", "print 'H at (-3, 4, 0) in cylindrical coordnates =',Hcyl,'mA/m'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "H at (-3, 4, 0) in cartesian coordnates = [ 38.2 28.65 23.87] mA/m\n", "H at (-3, 4, 0) in cylindrical coordnates = [ 0. -47.75 23.87] mA/m\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.5, Page number: 279

" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "#Variable Declaration\n", "\n", "i0=-10 #current through plane z=0 in A/m\n", "i4=10 #current through plane z=4 in A/m\n", "\n", "#Calculations\n", "\n", "H0a=0.5*i0*-1 #H in positive Y direction in A/m\n", "H4a=0.5*i4*-1*-1 #H in positive Y direction in A/m\n", "Ha=H0a+H4a #H at (1,1,1) in A/m \n", "H0b=0.5*i0*-1 #H in positive Y direction in A/m\n", "H4b=0.5*i4*-1 #H in negative Y direction in A/m\n", "Hb=H0b+H4b #H at (0,-3,10) in A/m\n", "\n", "#Results\n", "\n", "print 'H at (1,1,1) =',Ha,'A/m'\n", "print 'H at (0,-3,10) =',Hb,'A/m'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "H at (1,1,1) = 10.0 A/m\n", "H at (0,-3,10) = 0.0 A/m\n" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.7, Page number: 287

" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "\n", "import scipy.integrate\n", "\n", "#Calculation\n", "\n", "def B(z,p): \n", " return 0.5*p\n", "psy, err = scipy.integrate.dblquad(lambda p , z: B(z,p), \n", " 0, 5, lambda p: 1, lambda p: 2)\n", "\n", "#Result\n", "\n", "print 'Total magnetic flux crossing the surface phi=pi/2 is',psy,'Wb'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total magnetic flux crossing the surface phi=pi/2 is 3.75 Wb\n" ] } ], "prompt_number": 4 } ], "metadata": {} } ] }