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{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter14 : Electromagnetism"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_1 Page No. 421"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Amps-Turn (A.t) of Magneto-Motive Force (mmf) = 10.00 A.t\n"
]
}
],
"source": [
"# Calculate the ampere-turns of mmf for a coil with 2000 turns and a 5-mA current.\n",
"\n",
"# Given data\n",
"\n",
"I = 5*10**-3# # Current=5 mAmps\n",
"N = 2000# # No. of Turns=2000\n",
"\n",
"mmf = I*N#\n",
"print 'The Amps-Turn (A.t) of Magneto-Motive Force (mmf) = %0.2f A.t'%mmf"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_2 Page No. 421"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Turns necessary are : 150\n"
]
}
],
"source": [
"# A coil with 4 A is to provide a magnetizing force of 600 A\u0002 t. How many turns are necessary?\n",
"\n",
"# Given data\n",
"\n",
"I = 4# # Current=4 Amps\n",
"mmf = 600# # Magnetizing Force=600 A.t\n",
"\n",
"N = mmf/I#\n",
"print 'The Turns necessary are : ',N"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_3 Page No. 424"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Current necessary = 2 Amps\n"
]
}
],
"source": [
"# A coil with 400 turns must provide 800 A\u0002 t of magnetizing force. How much current is necessary?\n",
"\n",
"# Given data\n",
"\n",
"mmf = 800# # Magnetizing Force=800 A.t\n",
"N = 400# # No. of Turns=400\n",
"\n",
"I = mmf/N#\n",
"print 'The Current necessary = %0.f Amps'%I"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_4 Page No. 426"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Current necessary when a wire is connected to 6-V Battery = 2 Amps\n",
"The Amps-Turn (A.t) of Magneto-Motive Force (mmf) = 500 A.t\n"
]
}
],
"source": [
"# The wire in a solenoid of 250 turns has a resistance of 3 Ohms. (a)How much is the current when the coil is connected to a 6-V battery? (b) Calculate the ampereturns of mmf.\n",
"\n",
"# Given data\n",
"\n",
"V = 6# # Voltage=6 Volts\n",
"R = 3# # Resistance=3 Ohms\n",
"N = 250# # No. of Turns=250\n",
"\n",
"I = V/R#\n",
"print 'The Current necessary when a wire is connected to 6-V Battery = %0.f Amps'%I\n",
"\n",
"mmf = I*N#\n",
"print 'The Amps-Turn (A.t) of Magneto-Motive Force (mmf) = %0.f A.t'%mmf"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_5 Page No. 426"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Absolute u as B/H in CGS = 500 (G/Oe)\n",
"The Absolute u as B/H in SI = 6.300e-04 (T/(A.t/m))\n",
"i.e 630*10**-6 T/(A.t/m)\n"
]
}
],
"source": [
"# A magnetic material has a \u0003ur of 500. Calculate the absolute u\u0003 as B/H (a) in CGS units and (b) in SI units.\n",
"\n",
"# Given data\n",
"\n",
"ur = 500# # ur=500\n",
"uoa = 1# # uo for CGS Units=1\n",
"uob = 1.26*10**-6# # uo for SI Units=1.26 u\n",
"\n",
"ua = ur*uoa#\n",
"print 'The Absolute u as B/H in CGS = %0.f (G/Oe)'%ua\n",
"\n",
"ub = ur*uob#\n",
"print 'The Absolute u as B/H in SI = %0.3e (T/(A.t/m))'%ub\n",
"print 'i.e 630*10**-6 T/(A.t/m)'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example No. 14_6 Page No. 427"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The Flux density = 0.63 Tesla\n"
]
}
],
"source": [
"# u = 630*10**-\u00056 in SI units, calculate the flux density B that will be produced by the field intensity H equal to 1000 A.t/m.\n",
"\n",
"# Given data\n",
"\n",
"u = 630*10**-6# # u=630 micro T/(A.t/m)\n",
"H = 1000# # H=1000 A.t/m\n",
"\n",
"B = u*H#\n",
"print 'The Flux density = %0.2f Tesla'%B"
]
}
],
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|
