{ "metadata": { "name": "", "signature": "sha256:c6970542ad51432c833f98812d08f1e8865158ee25a859a74fb18804672e045b" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 10: Electrical measuring instruments and measurements

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

Example 1, page no. 116

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "Ia = 0.040;# in Amperes\n", "I = 50;# in Amperes\n", "ra = 25;# in ohms\n", "\n", "#calculation:\n", "Is = I - Ia\n", "V = Ia*ra\n", "Rs = V/Is\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n value of the shunt to be connected in parallel = \", round((Rs/1E-3),2),\" mohms\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " value of the shunt to be connected in parallel = 20.02 mohms" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 2, page no. 116

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "V = 100;# in volts\n", "I = 0.008;# in Amperes\n", "ra = 10;# in ohms\n", "\n", "#calculation:\n", "Rm = (V/I) - ra\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n value of the multiplier to be connected in series = \", (Rm/1E3),\" kohms\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " value of the multiplier to be connected in series = 12.49 kohms" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 3, page no. 119

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "fsd = 200;# in volts\n", "R1 = 250;# in ohms\n", "R2 = 2E6;# in ohms\n", "sensitivity = 10000;# in ohms/V\n", "V = 100; # in volts\n", "\n", "#calculation:\n", "Rv = sensitivity*fsd\n", "Iv = V/Rv\n", "Pv = V*Iv\n", "I1 = V/R1\n", "P1 = V*I1\n", "I2 = V/R2\n", "P2 = V*I2\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)the power dissipated by the voltmeter = \", (Pv/1E-3),\" mW\\n\"\n", "print \"\\n (b)the power dissipated by resistor 250 ohm = \", P1,\" W\\n\"\n", "print \"\\n (c)the power dissipated by resistor 2 Mohm = \", (P2/1E-3),\" mW\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)the power dissipated by the voltmeter = 5.0 mW\n", "\n", "\n", " (b)the power dissipated by resistor 250 ohm = 40.0 W\n", "\n", "\n", " (c)the power dissipated by resistor 2 Mohm = 5.0 mW" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 4, page no. 119

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "V = 10;# in volts\n", "fsd = 0.1;# in Amperes\n", "ra = 50;# in ohms\n", "R = 500;# in ohms\n", "\n", "#calculation:\n", "Ie = V/R\n", "Ia = V/(R + ra)\n", "Pa = Ia*Ia*ra\n", "PR = Ia*Ia*R\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)expected ammeter reading = \", (Ie/1E-3),\" mA\\n\"\n", "print \"\\n (b)Actual ammeter reading = \",round((Ia/1E-3),2),\" mA\\n\"\n", "print \"\\n (c)Power dissipated in the ammeter = \",round((Pa/1E-3),2),\" mW\\n\"\n", "print \"\\n (d)Power dissipated in the load resistor = \", round((PR/1E-3),2),\" mW\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)expected ammeter reading = 20.0 mA\n", "\n", "\n", " (b)Actual ammeter reading = 18.18 mA\n", "\n", "\n", " (c)Power dissipated in the ammeter = 16.53 mW\n", "\n", "\n", " (d)Power dissipated in the load resistor = 165.29 mW" ] } ], "prompt_number": 4 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 5, page no. 120

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "fsd = 100;# in volts\n", "R1 = 40E3;# in ohms\n", "R2 = 60E3;# in ohms\n", "sensitivity = 1600;# in ohms/V\n", "\n", "#calculation:\n", "V1 = (R1/(R1 + R2))*fsd\n", "Rv = fsd*sensitivity\n", "Rep = R1*Rv/(R1 + Rv)\n", "V1n = (Rep/(Rep + R2))*fsd\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)the value of voltage V1 with the voltmeter6 not connected = \", V1,\" V\\n\"\n", "print \"\\n (b)the voltage indicated by the voltmeter when connected between A and B = \",round(V1n,2),\" V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)the value of voltage V1 with the voltmeter6 not connected = 40.0 V\n", "\n", "\n", " (b)the voltage indicated by the voltmeter when connected between A and B = 34.78 V" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 6, page no. 120

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "I = 20;# in amperes\n", "R = 2;# in ohms\n", "Rw = 0.01;# in ohms\n", "\n", "#calculation:\n", "PR = I*I*R\n", "Rt = R + Rw\n", "Pw = I*I*Rt\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)the power dissipated in the load = \", PR,\" W\\n\"\n", "print \"\\n (b)the wattmeter reading. = \",Pw,\" W\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)the power dissipated in the load = 800 W\n", "\n", "\n", " (b)the wattmeter reading. = 804.0 W" ] } ], "prompt_number": 6 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 8, page no. 122

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "tc = 100E-6;# in s/cm\n", "Vc = 20;# in V/cm\n", "w = 5.2;# in cm ( width of one complete cycle )\n", "h = 3.6; # in cm ( peak-to-peak height of the display )\n", "\n", "#calculation:\n", "T = w*tc\n", "f = 1/T\n", "ptpv = h*Vc\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)the periodic time, T = \", (T/1E-3),\" msec\\n\"\n", "print \"\\n (b)Frequency, f = \",round(f,2),\" Hz\\n\"\n", "print \"\\n (c)the peak-to-peak voltage = \",ptpv,\" V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)the periodic time, T = 0.52 msec\n", "\n", "\n", " (b)Frequency, f = 1923.08 Hz\n", "\n", "\n", " (c)the peak-to-peak voltage = 72.0 V" ] } ], "prompt_number": 7 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 9, page no. 123

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "tc = 50E-3;# in s/cm\n", "Vc = 0.2;# in V/cm\n", "w = 3.5;# in cm ( width of one complete cycle )\n", "h = 3.4; # in cm ( peak-to-peak height of the display )\n", "\n", "#calculation:\n", "T = w*tc\n", "f = 1/T\n", "ptpv = h*Vc\n", "\n", "#Results \n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)the periodic time, T = \", (T/1E-3),\" msec\\n\"\n", "print \"\\n (b)Frequency, f = \",round(f,2),\" Hz\\n\"\n", "print \"\\n (c)the peak-to-peak voltage = \",ptpv,\" V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)the periodic time, T = 175.0 msec\n", "\n", "\n", " (b)Frequency, f = 5.71 Hz\n", "\n", "\n", " (c)the peak-to-peak voltage = 0.68 V" ] } ], "prompt_number": 8 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10, page no. 123

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "tc = 500E-6;# in s/cm\n", "Vc = 5;# in V/cm\n", "w = 4;# in cm ( width of one complete cycle )\n", "h = 5; # in cm ( peak-to-peak height of the display )\n", "\n", "#calculation:\n", "T = w*tc\n", "f = 1/T\n", "ptpv = h*Vc\n", "Amp = ptpv/2\n", "Vrms = Amp/(2**0.5)\n", "\n", "#Results \n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)Frequency, f = \",f,\" Hz\\n\"\n", "print \"\\n (b)the peak-to-peak voltage = \",ptpv,\" V\\n\"\n", "print \"\\n (c)Amplitude = \",Amp,\" V\\n\"\n", "print \"\\n (d)r.m.s voltage = \",round(Vrms,2),\" V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)Frequency, f = 500.0 Hz\n", "\n", "\n", " (b)the peak-to-peak voltage = 25 V\n", "\n", "\n", " (c)Amplitude = 12.5 V\n", "\n", "\n", " (d)r.m.s voltage = 8.84 V" ] } ], "prompt_number": 9 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11, page no. 123

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "\n", "#initializing the variables:\n", "tc = 100E-6;# in s/cm\n", "Vc = 2;# in V/cm\n", "w = 5;# in cm ( width of one complete cycle for both waveform )\n", "h1 = 2; # in cm ( peak-to-peak height of the display )\n", "h2 = 2.5; # in cm ( peak-to-peak height of the display\n", "\n", "#calculation:\n", "T = w*tc\n", "f = 1/T\n", "ptpv1 = h1*Vc\n", "Vrms1 = ptpv1/(2**0.5)\n", "ptpv2 = h2*Vc\n", "Vrms2 = ptpv2/(2**0.5)\n", "phi = 0.5*360/w\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)Frequency, f = \",f,\" Hz\\n\"\n", "print \"\\n (b1)r.m.s voltage of 1st waveform = \",round(Vrms1,2),\" V\\n\"\n", "print \"\\n (b2)r.m.s voltage of 2nd waveform = \",round(Vrms2,2),\" V\\n\"\n", "print \"\\n (c)Phase difference = \",phi,\"deg\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)Frequency, f = 2000.0 Hz\n", "\n", "\n", " (b1)r.m.s voltage of 1st waveform = 2.83 V\n", "\n", "\n", " (b2)r.m.s voltage of 2nd waveform = 3.54 V\n", "\n", "\n", " (c)Phase difference = 36.0 deg" ] } ], "prompt_number": 11 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 12, page no. 127

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "rP1 = 3;# ratio of two powers\n", "rP2 = 20;# ratio of two powers\n", "rP3 = 400;# ratio of two powers\n", "rP4 = 1/20;# ratio of two powers\n", "\n", "#calculation:\n", "X1 = 10*(1/2.303)*math.log(3)\n", "X2 = 10*(1/2.303)*math.log(20)\n", "X3 = 10*(1/2.303)*math.log(400)\n", "X4 = 10*(1/2.303)*math.log(1/20)\n", "\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n (a)decibel power ratio for power ratio 3 = \",round(X1,2),\" dB\\n\"\n", "print \"\\n (b)decibel power ratio for power ratio 20 = \",round(X2,2),\" dB\\n\"\n", "print \"\\n (c)decibel power ratio for power ratio 400 = \",round(X3,2),\" dB\\n\"\n", "print \"\\n (d)decibel power ratio for power ratio 1/20 = \",round(X4,2),\" dB\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " (a)decibel power ratio for power ratio 3 = 4.77 dB\n", "\n", "\n", " (b)decibel power ratio for power ratio 20 = 13.01 dB\n", "\n", "\n", " (c)decibel power ratio for power ratio 400 = 26.02 dB\n", "\n", "\n", " (d)decibel power ratio for power ratio 1/20 = -13.01 dB" ] } ], "prompt_number": 12 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 13, page no. 127

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "I2 = 0.020;# in ampere\n", "I1 = 0.005;# in ampere\n", "\n", "#calculation:\n", "X = 20*math.log10(math.e)*math.log(I2/I1)\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n decibel current ratio = \",round(X,2),\" dB\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " decibel current ratio = 12.04 dB\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 14, page no. 128

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "rP = 0.06;# power ratios rP = P2/P1\n", "\n", "#calculation:\n", "X = 10*math.log10(math.e)*math.log(rP)\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n decibel Power ratios = \",round(X,2),\" dB\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " decibel Power ratios = -12.22 dB\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 15, page no. 128

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "X = 14;# decibal power ratio in dB\n", "P1 = 0.008;# in Watt\n", "\n", "#calculation:\n", "rP = 10**(X/10)\n", "P2 = rP*P1\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n output power P2 = \",round(P2,2),\" W\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " output power P2 = 0.2 W" ] } ], "prompt_number": 15 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 16, page no. 128

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "X = 27;# Voltage gain in decibels\n", "V2 = 4;# output voltage in Volts\n", "\n", "#calculation:\n", "V1 = V2/(10**(27/20))\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n input Voltage V1 = \",round(V1,2),\" V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " input Voltage V1 = 0.18 V" ] } ], "prompt_number": 16 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 17, page no. 129

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "R2 = 100;# in ohms\n", "R3 = 400;# in ohms\n", "R4 = 10;# in ohms\n", "\n", "#calculation:\n", "R1 = R2*R3/R4\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n unknown resistance, R1 = \",R1,\" Ohms\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " unknown resistance, R1 = 4000.0 Ohms" ] } ], "prompt_number": 17 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 18, page no. 130

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "E1 = 1.0186;# in Volts\n", "l1 = 0.400;# in m\n", "l2 = 0.650;# in m\n", "\n", "#calculation:\n", "E2 = (l2/l1)*E1\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n the e.m.f. of a dry cell = \",round(E2,2),\" Volts\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " the e.m.f. of a dry cell = 1.66 Volts" ] } ], "prompt_number": 18 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 19, page no. 132

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "I = 0.0025;# in Amperes\n", "R = 5000;# in ohms\n", "e1 = 0.4;# in %\n", "e2 = 0.5;# in %\n", "\n", "#calculation:\n", "V = I*R\n", "em = e1 + e2\n", "Ve = em*V/100\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n voltage V = \",V,\"V(+-)\",Ve,\"V\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " voltage V = 12.5 V(+-) 0.1125 V" ] } ], "prompt_number": 19 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 20, page no. 132

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "I = 6.25;# in Amperes\n", "Im = 10;# max in Amperes\n", "V = 36.5;# in volts\n", "Vm = 50;# max in volts\n", "e = 2;# in %\n", "\n", "#calculation:\n", "R = V/I\n", "Ve = e*Vm/100 \n", "Ve1 = Ve*100/V# in %\n", "Ie = e*Im/100\n", "Ie1 = Ie*100/I# in %\n", "em = Ve1 + Ie1\n", "Re = em*R/100\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n Resistance R = \",R,\" ohms(+-)\",Re,\" ohms\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " Resistance R = 5.84 ohms(+-) 0.34688 ohms" ] } ], "prompt_number": 20 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 21, page no. 133

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from __future__ import division\n", "import math\n", "#initializing the variables:\n", "R1 = 1000;# in ohms\n", "R2 = 100;# in ohms\n", "R3 = 432.5;# in ohms\n", "e1 = 1;# in %\n", "e2 = 0.5;# in %\n", "e3 = 0.2;# in %\n", "\n", "#calculation:\n", "Rx = R2*R3/R1\n", "em = e1 + e2 + e3\n", "Re = em*Rx/100\n", "\n", "#Results\n", "print \"\\n\\n Result \\n\\n\"\n", "print \"\\n Resistance R = \",Rx,\" ohms(+-)\",Re,\" ohms\\n\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " Result \n", "\n", "\n", "\n", " Resistance R = 43.25 ohms(+-) 0.73525 ohms" ] } ], "prompt_number": 21 } ], "metadata": {} } ] }