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{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 12: Resistance and DC Circuits"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.1, Page 237"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Magnitude, I4 = -3 A\n"
]
}
],
"source": [
"#Initialization\n",
"i1=8 #current in Amp\n",
"i2=1 #current in Amp\n",
"i3=4 #current in Amp\n",
"\n",
"#Calculation\n",
"i4=i2+i3-i1 #current in Amp\n",
"\n",
"#Results\n",
"print'Magnitude, I4 = %d A'%i4"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.2, Page 239"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"#Initialization\n",
"e=12 #EMF source in volt\n",
"v1=3 #node voltage\n",
"v3=3 #node voltage\n",
"\n",
"#Calculation\n",
"v2=v1+v3-e #node voltage\n",
"\n",
"#Results\n",
"print'V2 = %d V'%v2"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.4, Page 242"
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Voc = 10 V\n",
"R = 100 ohm\n"
]
}
],
"source": [
"import numpy as np\n",
"\n",
"#We have used method II for solving our problem by using simultaneous equations\n",
"\n",
"a = np.array([[25,-2],[400,-8]]) \n",
"b = np.array([[50],[3200]])\n",
"c=np.linalg.solve(a,b)\n",
"\n",
"print'Voc = %d V'%c[0]\n",
"print'R = %d ohm'%c[1]\n",
" "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.5, Page 244"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Voltage, V = 7.14\n"
]
}
],
"source": [
"#Initialization\n",
"r1=100 #Resistance in Ohm\n",
"r2=200 #Resistance in Ohm\n",
"r3=50 #Resistance in Ohm\n",
"v1=15 #voltage source\n",
"v2=20 #voltage source\n",
"\n",
"#Calculation\n",
"#Considering 15 V as a source & replace the other voltage source by its internal resistance,\n",
"r11=(r2*r3)*(r2+r3)**-1 #resistance in parallel\n",
"v11=v1*(r11/(r1+r11)) #voltage\n",
"#Considering 20 V as a source & replace the other voltage source by its internal resistance,\n",
"r22=(r1*r3)*(r1+r3)**-1 #resistance in parallel\n",
"v22=v2*(r22/(r2+r22)) #voltage\n",
"\n",
"#output of the original circuit\n",
"v33=v11+v22\n",
"\n",
"\n",
"\n",
"#Results\n",
"print'Voltage, V = %.2f'%v33"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.6, Page 246"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Output Current, I = 1.67 A\n"
]
}
],
"source": [
"#Initialization\n",
"r1=10 #Resistance in Ohm\n",
"r2=5 #Resistance in Ohm\n",
"v2=5 #voltage source\n",
"i=2 #current in Amp\n",
"\n",
"#Calculation\n",
"#Considering 5 V as a source & replace the current source by its internal resistance,\n",
"i1=v2*(r1+r2)**-1 #current using Ohms law\n",
"#Considering current source & replace the voltage source by its internal resistance,\n",
"r3=(r1*r2)*(r1+r2)**-1 #resistance in parallel\n",
"v3=i*r3 #voltage using Ohms law\n",
"i2=v3*r2**-1 #current using Ohms law\n",
"i3=i1+i2 #total current\n",
"\n",
"#Results\n",
"print'Output Current, I = %.2f A'%i3"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.8, Page 251"
]
},
{
"cell_type": "code",
"execution_count": 22,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"V2 = 33.04 V\n",
"V3 = 43.15 V\n",
"Current, I1 = 1.73 A\n"
]
}
],
"source": [
"import numpy as np\n",
"r=25 #resistance in ohm\n",
"\n",
"#We have used for solving our problem by using simultaneous equations\n",
"\n",
"a = np.array([[(-13*60**-1),(1*20**-1)],[(1*60**-1),(-9*100**-1)]]) \n",
"b = np.array([[-5],[-100*30**-1]])\n",
"c=np.linalg.solve(a,b)\n",
"i1=c[1]/r #required current\n",
"\n",
"print'V2 = %.2f V'%c[0] #wrong answer in textbook\n",
"print'V3 = %.2f V'%c[1] #wrong answer in textbook\n",
"print'Current, I1 = %.2f A'%i1\n",
" "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.9, Page 253"
]
},
{
"cell_type": "code",
"execution_count": 34,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"I1 = 326 mA\n",
"I2 = 33 mA\n",
"I3 = 53 mA\n",
"Voltage, Ve = 0.197 V\n"
]
}
],
"source": [
"import numpy as np\n",
"re=10 #resistance in ohm\n",
"\n",
"#We have used for solving our problem by using simultaneous equations\n",
"\n",
"a = np.array([[(-160),(20), (30)],[(20),(-210), (10)], [(30),(10), (-190)]]) \n",
"b = np.array([[-50],[0],[0]])\n",
"c=np.linalg.solve(a,b)\n",
"ve=re*(c[2]-c[1])\n",
"\n",
"print'I1 = %d mA'%(c[0]*10**3) #current I1\n",
"print'I2 = %d mA'%(c[1]*10**3) #current I2\n",
"print'I3 = %d mA'%(c[2]*10**3) #current I3\n",
"print'Voltage, Ve = %.3f V'%ve\n",
" "
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": []
}
],
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"kernelspec": {
"display_name": "Python [Root]",
"language": "python",
"name": "Python [Root]"
},
"language_info": {
"codemirror_mode": {
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"file_extension": ".py",
"mimetype": "text/x-python",
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|
