{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# CHAPTER 7: LOW, HIGH AND PRECISE RESISTANCE MEASUREMENTS\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-1, Page Number: 165"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"R= 990 ohm\n"
]
}
],
"source": [
"import math\n",
"\n",
"#Variable Declaration\n",
"\n",
"I=0.5 #in A\n",
"E1=500 #E+Ea in V\n",
"Ra=10 #in ohm\n",
"\n",
"#Calculations\n",
"R1=E1/I #in ohm\n",
"R=R1-Ra #in ohm\n",
"\n",
"#Result\n",
"print \"R=\",int(R),\"ohm\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-2, Page Number: 166"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Voltmeter Reading= 495.0 V\n",
"Ammeter Reading= 0.5 A\n"
]
}
],
"source": [
"import math\n",
"\n",
"#Variable Declaration\n",
"\n",
"sensitivity=10**3 #in ohm/V\n",
"V=1000.0 #in V \n",
"R=990.0 #in ohm\n",
"Ra=10.0 #in ohm\n",
"supply_voltage=500 #in V \n",
"\n",
"\n",
"#Calculations\n",
"Rv=V*sensitivity #in ohm\n",
"R1=Rv*R/(Rv+R) #in ohm \n",
"voltmeter_reading=supply_voltage*R1/(Ra+R1) #in volt \n",
"ammeter_reading=supply_voltage/R1 #in A\n",
"\n",
"#Results\n",
"print \"Voltmeter Reading=\",round(voltmeter_reading,1),\"V\"\n",
"print \"Ammeter Reading=\",round(ammeter_reading,1),\"A\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-3, Page Number: 166"
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"For V=495 V,I=0.5 A, R= 990.0 ohm\n",
"For V=500 V,I=0.5 A, R= 1000.0 ohm\n"
]
}
],
"source": [
"import math\n",
"\n",
"\n",
"#For figure 7-1(a)\n",
"voltmeter_reading=495 #in V\n",
"ammeter_reading=0.5 #in A\n",
"R=voltmeter_reading/ammeter_reading #in ohm\n",
"print \"For V=495 V,I=0.5 A, R=\",R,\"ohm\"\n",
"\n",
"#For figure 7-1(b)\n",
"voltmeter_reading=500 #in V\n",
"ammeter_reading=0.5 #in A\n",
"R=voltmeter_reading/ammeter_reading #in ohm\n",
"\n",
"print \"For V=500 V,I=0.5 A, R=\",R,\"ohm\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-4, Page Number: 169"
]
},
{
"cell_type": "code",
"execution_count": 12,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"R= 2.755 kilo ohm\n",
"Measurement Range is 500.0 ohm to 4.0 kilo ohm\n"
]
}
],
"source": [
"import math \n",
"\n",
"#Variable Declaration\n",
"\n",
"#Bridge Resistances\n",
"P=3.5*10**3 #in ohm\n",
"Q=7*10**3 #in ohm\n",
"S=5.51*10**3 #in ohm \n",
"\n",
"#Calculations\n",
"\n",
"R=S*P/Q #Equation for unknown resistance in a balanced bridge(ohm)\n",
"\n",
"#When S=1 kilo ohm\n",
"S=1*10**3 #in ohm\n",
"R1=S*P/Q #in ohm \n",
"\n",
"#When S=8 kilo ohm\n",
"S=8*10**3 #in ohm \n",
"R2=S*P/Q #in ohm\n",
"\n",
"print \"R=\",round(R/1000,3),\"kilo ohm\"\n",
"print \"Measurement Range is\",round(R1),\"ohm to \",round(R2/1000),\"kilo ohm\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-5, Page Number: 169"
]
},
{
"cell_type": "code",
"execution_count": 19,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
" Error in R=± 0.2 %\n",
"R= 2.755 kilo ohm ± 0.2 %\n",
"R= 2.755 kilo ohm ± 5.5 %\n",
"R= 2.7495 kilo ohm to 2.7605 kilo ohm\n"
]
}
],
"source": [
"import math\n",
"\n",
"#Variable Declaration\n",
"#Bridge Resistances\n",
"P=3.5*10**3 #in ohm\n",
"Q=7*10**3 #in ohm\n",
"S=5.51*10**3 #in ohm \n",
"R=2.755*10**3 #in ohm \n",
"p_accuracy=0.05 #in percentage \n",
"q_accuracy=0.05 #in percentage\n",
"s_accuracy=0.1 #in percentage \n",
"\n",
"#Calculation\n",
"error_r=p_accuracy+q_accuracy+s_accuracy #in percentage\n",
"Rmax=R+R*error_r/100.0 #in ohm\n",
"Rmin=R-R*error_r/100.0 #in ohm \n",
"\n",
"#Result\n",
"\n",
"print \"Error in R=±\",round(error_r,1),\"%\"\n",
"print \"R=\",round(R/1000,3),\"kilo ohm ±\",round(error_r,1),\"%\"\n",
"print \"R=\",round(R/1000,3),\"kilo ohm ±\",round(R*error_r/100.0,1),\"%\"\n",
"print \"R=\",round(Rmin/1000,4),\"kilo ohm to \",round(Rmax/1000,4),\"kilo ohm\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-6, Page Number: 172"
]
},
{
"cell_type": "code",
"execution_count": 58,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Minimum Change in R is 5.9 ohm\n"
]
}
],
"source": [
"import math\n",
"\n",
"#Variable Declaration\n",
"\n",
"P=3.5*10**3 #in ohm\n",
"Q=7*10**3 #in ohm\n",
"S=4*10**3 #in ohm\n",
"R=2*10**3 #in ohm\n",
"Eb=10\n",
"Ig=10**-6 #in A/mm\n",
"Rg=2.5*10**3 #in ohm\n",
"\n",
"#Calculations\n",
"r=P*R/(P+R)+Q*S/(Q+S) #R=P||R+Q||S in ohm\n",
"dV=Ig*(r+Rg) # Smallest voltage change in V \n",
"\n",
"Vr=Eb*R/(P+R) #Voltage across R(Voltage Divider Rule), in V \n",
"V=Vr+dV #in V \n",
"Vp=Eb-V #KVL \n",
"Ip=Vp/P #Ohm's Law\n",
"Ir=Ip \n",
"dR=round(V,5)/round(Ir,6)-R #in ohm\n",
"\n",
"\n",
"print \"Minimum Change in R is\",round(dR,1),\"ohm\"\n",
"\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-7, Page Number: 176"
]
},
{
"cell_type": "code",
"execution_count": 59,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"R/P=S/Q= 10 / 15\n"
]
}
],
"source": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"S=0.10 #in ohm\n",
"Q=0.15 #in ohm(Approximately equal to 0.15)\n",
"\n",
"#Result\n",
"print \"R/P=S/Q= \",int(S*100),\"/\",int(Q*100)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 7-8, Page Number: 180"
]
},
{
"cell_type": "code",
"execution_count": 51,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Volume resistance= 6.7e+09 ohm\n",
"Surface resistance= 2.9e+09 ohm\n"
]
}
],
"source": [
"import math\n",
"\n",
"#Variable Declaration\n",
"E=10000 #in Volt\n",
"Iv=1.5*10**-6 #in A\n",
"rv=E/Iv #Volume resistance in ohm \n",
"\n",
"#Surface leakage Resistance\n",
"\n",
"It=5*10**-6 #in A\n",
"Is=It-Iv #KCL \n",
"rs=E/Is #Surface Resistance in ohm\n",
"\n",
"#Results\n",
"print \"Volume resistance=\",'%.1e' %rv,\"ohm\"\n",
"print \"Surface resistance=\",'%.1e' %rs,\"ohm\"\n",
"\n"
]
}
],
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