{
"metadata": {
"name": "",
"signature": "sha256:1f51544adf15fc8ba28e47ac7da1a371a1d8835331773ecfcfa211468f9b325d"
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"UNIT-5 Electricity"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.1,Page no:152"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"n=10**6 #no. of electrons\n",
"e=1.6*10**-19 #charge on an electron in C\n",
"\n",
"#Calculation\n",
"q=n*e #calculating total charge\n",
"t=10**-3 #time in second\n",
"I=q/t #calculating current\n",
"\n",
"#Result\n",
"print\"Current flowing = \",I,\"Ampere\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current flowing = 1.6e-10 Ampere\n"
]
}
],
"prompt_number": 71
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.2,Page no:152"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"I=300*10**-3 #current n Ampere\n",
"t=60 #time in second\n",
"e=1.6*10**-19 #chatge on electron in C\n",
"\n",
"#Calculation\n",
"q=I*t #calculating charge\n",
"n=q/e #calculating no of electrons\n",
"\n",
"#Result\n",
"print\"No. of electrons = \",n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"No. of electrons = 1.125e+20\n"
]
}
],
"prompt_number": 20
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.3,Page no:154"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"V=200 #voltage in volt\n",
"R=100 #resistance in Ohm\n",
"e=1.6*10**-19 #charge on an electron in C\n",
"\n",
"#Calculation\n",
"I=V/R #Ohm's law\n",
"t=1 #time in second\n",
"q=I*t #calculating charge\n",
"n=q/e #calculating no of electrons\n",
"\n",
"#Result\n",
"print\"No. of electrons = \",n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"No. of electrons = 1.25e+19\n"
]
}
],
"prompt_number": 72
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.4,Page no:156"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"l=15 #length in m\n",
"A=6*10**-7 #area in m square\n",
"R=5 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"p=(A*R)/l #calculating resistivity\n",
"\n",
"#Result\n",
"print\"Resistivity= \",p,\"Ohm metre\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistivity= 2e-07 Ohm metre\n"
]
}
],
"prompt_number": 73
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.5,Page no:157"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"l=0.1 #length in m\n",
"A=10**-4 #area in m square\n",
"R=0.01 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"p=(A*R)/l #calculating resistivity\n",
"\n",
"#Result\n",
"print\"Resistivity = \",p,\"Ohm metre\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistivity = 1e-05 Ohm metre\n"
]
}
],
"prompt_number": 74
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.6,Page no:157"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"import math \n",
"\n",
"#Variable declaration\n",
"L=1 #length in m\n",
"r=0.2*10**-3 #radius in m\n",
"R=2 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"A=math.pi*(r)**2 #calculating area\n",
"P=(R*A)/L #calculating resistivity\n",
"\n",
"#Result\n",
"print\"Resistivity =%.2g\"%P,\"Ohm.metre\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistivity =2.5e-07 Ohm.metre\n"
]
}
],
"prompt_number": 38
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.7,Page no:158"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R1=5 #resisitance in Ohm\n",
"\n",
"#Calculation\n",
"#A2=A/3\n",
"#R2/5=3l*3/A*A/l\n",
"#R2=9*5\n",
"\n",
"R2=9*R1 #calculating using R2/A1=(l2/A2)*(A1/l1)\n",
"print\"Resisitance = \",R2,\"Ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resisitance = 45 Ohm\n"
]
}
],
"prompt_number": 75
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.8,Page no:159"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R1=5 #resisitance in Ohm\n",
"\n",
"#Calculation\n",
"#A2=A/2\n",
"#R1=rho*l1/A1*R2\n",
"#R2=rho*l2/A2\n",
"#R2/R1=A1/l1\n",
"R2=4*R1 #calculating using R2/A1=(l2/A2)*(A1/l1)\n",
"\n",
"#Result\n",
"print\"Resisitance= \",R2,\"Ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resisitance= 20 Ohm\n"
]
}
],
"prompt_number": 70
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.9,Page no:162"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R1=2 #resisitance in Ohm\n",
"R2=4 #resistance in Ohm\n",
"R3=5 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"R=(R1**-1)+(R2**-1)+(R3**-1) #calculating parallel resistance\n",
"Rp=(1/R) \n",
"\n",
"#Result\n",
"print\"Resisitance = \",Rp,\"Ohm\"\n",
"print\"\\nNOTE:Incorrect answer in book\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resisitance = 1.05263157895 Ohm\n",
"\n",
"NOTE:Incorrect answer in book\n"
]
}
],
"prompt_number": 39
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.10,Page no:163"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from scipy.optimize import fsolve \n",
"\n",
"#Variable declaration\n",
"Rs=40 #resisitance in Ohm\n",
"\n",
"#Calculation\n",
"#R1+R2=40\n",
"#R1*R2=256\n",
"#R1=256/R2\n",
"#Putting this value in eq 1:\n",
"#(256/R2)+R2=40\n",
"from sympy import solve, symbols, pprint\n",
"R2= symbols('R2')\n",
"a=1\n",
"b=-40\n",
"c=256\n",
"f = a*R2**2 + b*R2 + c\n",
"solution = solve(f, R2)\n",
"\n",
"#Result\n",
"print\"When R2=\",solution[0],\"Ohm R1=\",solution[1],\"Ohm\"\n",
"print\"When R2=\",solution[1],\"Ohm R1=\",solution[0],\"Ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"When R2= 8 Ohm R1= 32 Ohm\n",
"When R2= 32 Ohm R1= 8 Ohm\n"
]
}
],
"prompt_number": 24
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.11,Page no:164"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"V=2.0 #in volts\n",
"R1=30.0 #resisitance in Ohm\n",
"R2=60.0 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"Rp=(R1*R2)/(R1+R2) #calculating parallel resistance\n",
"I=V/Rp #Ohm's law\n",
"\n",
"#Result\n",
"print\"Resisitance = \",Rp,\"Ohm\"\n",
"print\"Current = \",I,\"A\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resisitance = 20.0 Ohm\n",
"Current = 0.1 A\n"
]
}
],
"prompt_number": 26
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.12,Page no:165"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R1=2.0 #resisitance in Ohm\n",
"R2=3.0 #resistance in Ohm\n",
"R3=1.0 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"Rp=(R1*R2)/(R1+R2) #calculating parallel resistance\n",
"R=Rp+1.0 #1 Ohm in series\n",
"Rs=(R1+R2+R3) #series resistances\n",
"Rp=(1.0/R1)+(1.0/R2)+(1.0/R3) #calculating parallel resistance\n",
"\n",
"#Result\n",
"print\"(1)Equivalent Resisitance= \",R,\"Ohm\" \n",
"print\"(2)All resistances in series = \",Rs,\"Ohm\"\n",
"print\"(3)All in Parallel = \",(1/Rp),\"Ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(1)Equivalent Resisitance= 2.2 Ohm\n",
"(2)All resistances in series = 6.0 Ohm\n",
"(3)All in Parallel = 0.545454545455 Ohm\n"
]
}
],
"prompt_number": 76
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.13,Page no:166"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"V=20 #voltage in Volts\n",
"R1=2.0 #resisitance in Ohm\n",
"R2=4.0 #resistance in Ohm\n",
"R3=5.0 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"Rp=(1/R1)+(1/R2)+(1/R3) #calculating parallel resistance\n",
"R=1/Rp #Parallel\n",
"I1=V/R1 #calculating current through R1\n",
"I2=V/R2 #calculating current through R2\n",
"I3=V/R3 #calculating current through R3\n",
"I=V/R #calculating total current\n",
"\n",
"\n",
"#Result\n",
"print\"(a)Equivalent Resisitance = \",R,\"Ohm\"\n",
"print\"Current through R1 = \",I1,\"Ampere\"\n",
"print\"Current through R2 = \",I2,\"Ampere\" \n",
"print\"Total current = \",I,\"Ampere\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a)Equivalent Resisitance = 1.05263157895 Ohm\n",
"Current through R1 = 10.0 Ampere\n",
"Current through R2 = 5.0 Ampere\n",
"Total current = 19.0 Ampere\n"
]
}
],
"prompt_number": 30
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.14,Page no:166"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration\n",
"R=7 #Total resistanc of combination\n",
"\n",
"#Calculation\n",
"def f(n):\n",
" Rp = 6*(1/n) #resistance in parallel\n",
" return(R-Rp-5)\n",
"n=fsolve(f,1)\n",
"\n",
"#Result\n",
"print\"n=\",n[0]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"n= 3.0\n"
]
}
],
"prompt_number": 33
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.15,Page no:173"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R1=2 #resistance in Ohm\n",
"R2=6 #resistance in Ohm\n",
"R3=3 #resistance in Ohm\n",
"V=24 #voltage in volts\n",
"R=8 #resistance in Ohm\n",
"\n",
"#Calculation\n",
"I=V/R #Ohm's Law\n",
"V1=I*R1 #Ohm's Law\n",
"V2=I*R2 #Ohm's Law\n",
"V3=I*R3 #Ohm's Law\n",
"\n",
"#Result\n",
"print\"Current = \",I,\"Ampere\" \n",
"print\"Voltage drop across R1 = \",V1,\"Volts\"\n",
"print\"Voltage drop across R2 = \",V2,\"Volts\" \n",
"print\"Voltage drop across R3 = \",V3,\"Volts\"\n",
"print\"\\nNOTE:Wrong answer of R3 in book\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current = 3 Ampere\n",
"Voltage drop across R1 = 6 Volts\n",
"Voltage drop across R2 = 18 Volts\n",
"Voltage drop across R3 = 9 Volts\n",
"\n",
"NOTE:Wrong answer of R3 in book\n"
]
}
],
"prompt_number": 36
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.16,Page no:173"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"R=15 #resistance in Ohm\n",
"print\"KVL: 16I1+15I2=6 (1)\" #KVL equation\n",
"I1=-1.66 #from(1)\n",
"I2=2.17 #from (1)\n",
"#Calculation\n",
"V=(I1+I2)*R #calculating potential difference\n",
"\n",
"#Result\n",
"print\"Potential difference= \",V,\"Volt\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"KVL: 16I1+15I2=6 (1)\n",
"Potential difference= 7.65 Volt\n"
]
}
],
"prompt_number": 37
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.17,Page no:174"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"print\"3I1-I2-1=0 (1)\" #KVL equation\n",
"print\"3I1-I2+2I=2 (2)\" #KVL equation\n",
"print\"3I1-I1+2I=2 (3)\" #KVL equation\n",
"\n",
"#Variable declaration\n",
"I1=4/17.0 #from (1)(2)(3)through AB \n",
"I2=-2/17.0 #from (1)(2)(3)through BD\n",
"I=3*I1+I2 #from (1)(2)(3)through main circuit\n",
"\n",
"#Calculation\n",
"Ibc=I1-I2 #calculating current in BC\n",
"Iad=I-I1 #calculating current in AD\n",
"Idc=I-I1+I2 #calculating current in DC\n",
"\n",
"#Result\n",
"print\"Current in branch BC = \",Ibc,\"Ampere\"\n",
"print\"NOTE:Calculation mistake in book while calculating for BC\"\n",
"print\"Current in branch AD = \",Iad,\"Ampere\"\n",
"print\"Current in branch DC = \",Idc,\"Ampere\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"3I1-I2-1=0 (1)\n",
"3I1-I2+2I=2 (2)\n",
"3I1-I1+2I=2 (3)\n",
"Current in branch BC = 0.352941176471 Ampere\n",
"NOTE:Calculation mistake in book while calculating for BC\n",
"Current in branch AD = 0.352941176471 Ampere\n",
"Current in branch DC = 0.235294117647 Ampere\n"
]
}
],
"prompt_number": 77
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.18,Page no:176"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"P=10 #Ohm\n",
"Q=3 #Ohm\n",
"R=12 #Ohm\n",
"S=6 #Ohm\n",
"G=20 #Ohm\n",
"\n",
"\n",
"#Calculation\n",
"print\"-12I+22I1+IgG=0 (1)\" #KVL\n",
"print\"6I-9I1+29Ig=0 (2)\" #KVL\n",
"print\"13I1-3Ig=2 (3)\" #KVL\n",
"#From above equations\n",
"import numpy as np\n",
"a = np.array([[-12,22,20],[6,-9,29],[0,13,-3]]) \n",
"b = np.array([[0],[0],[2]])\n",
"np.linalg.solve(a,b)\n",
"\n",
"\n",
"#Result\n",
"print\"Current through Galvanometer = \",round(Ig*1000,2),\"mA\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"-12I+22I1+IgG=0 (1)\n",
"6I-9I1+29Ig=0 (2)\n",
"13I1-3Ig=2 (3)\n",
"Current through Galvanometer = 7.8 mA\n"
]
}
],
"prompt_number": 78
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.19,Page no:179"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration \n",
"P=500 #power in Watts\n",
"V=200 #voltage in Volts\n",
"V1=160 #voltage in Volts\n",
"\n",
"#Calculation\n",
"R=(V**2)/P #using P=V**2*R\n",
"P1=(V1**2)/R #calculating power\n",
"Dp=500-P1 #drop in heat\n",
"D=(Dp*100)/500 #percentage drop\n",
"\n",
"#Result\n",
"print\"Resistance= \",R,\"Ohm\"\n",
"print\"% Drop in heat production = \",D,\"%\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistance= 80 Ohm\n",
"% Drop in heat production = 36 %\n"
]
}
],
"prompt_number": 79
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.20,Page no:180"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration\n",
"P1=100 #power in Watts\n",
"P2=500 #power in Watts\n",
"\n",
"#Calculation\n",
"P=P2/P1 #ratio\n",
"\n",
"#Result\n",
"print \"P=\",P\n",
"print\"P>0,I2=5I Therefore I2>I1\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"P= 5\n",
"P>0,I2=5I Therefore I2>I1\n"
]
}
],
"prompt_number": 80
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.21,Page no:181"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration \n",
"t=1200 #time in second\n",
"P=100 #power in Watts\n",
"V=230 #voltage in Volts\n",
"\n",
"#Calculation\n",
"R=(V**2)/P #calculating resistance\n",
"V1=115 #supply voltage in Volts\n",
"E=((V1**2)*t)/R #calculating energy\n",
"\n",
"#Result\n",
"print\"Energy dissipated by bulb = \",E,\"J\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Energy dissipated by bulb = 30000 J\n"
]
}
],
"prompt_number": 81
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.22,Page no:181"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration\n",
"P=10**4 #power in Watts\n",
"V=250 #voltage in Volts\n",
"R=0.2 #resistance in ohm\n",
"\n",
"#Calculation\n",
"Pl=((P/V)*(P/V))*R #calculating power loss\n",
"print P1\n",
"E=P/(Pl+P) #calculating efficiency\n",
"\n",
"#Result\n",
"print\"Percent Efficiency = \",round(E*100),\"%\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"100\n",
"Percent Efficiency = 97.0 %\n"
]
}
],
"prompt_number": 56
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.23,Page no:182"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Variable declaration \n",
"P=100.0 #power in Watts\n",
"V=220.0 #voltage in Volts\n",
"\n",
"#Calculation\n",
"I=P/V #Current in Ampere\n",
"R=V/I #resistance\n",
"\n",
"#Result\n",
"print\"Current = \",round(I,3),\"A\" \n",
"print\"Resistance=\",R,\"Ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Current = 0.455 A\n",
"Resistance= 484.0 Ohm\n"
]
}
],
"prompt_number": 59
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example no:5.24,Page no:182"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"#Variable declaration \n",
"V=50 #voltage in Volts\n",
"I=12 #Current in Ampere\n",
"\n",
"#Calculation\n",
"P=V*I #power\n",
"Pd=P*0.7 #power dissipated\n",
"R=(Pd/(I)**2) \n",
"\n",
"#Result\n",
"print\"Resistance = \",round(R,2),\"Ohm\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistance = 2.92 Ohm\n"
]
}
],
"prompt_number": 82
}
],
"metadata": {}
}
]
}