{
"metadata": {
"name": "",
"signature": "sha256:04d8806c560b3bd07d87813351e39839b8f2c2b391de8dcf1afa3dc83f2be11d"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 14 Earths magnetism"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.3 Page no 433"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"a=60 #Degree\n",
"Bh=0.16 #G\n",
"\n",
"#Calculation\n",
"import math\n",
"B=Bh/cos(a*3.14/180.0)\n",
"\n",
"#Result\n",
"print\"Magnitude of earth's field is\", round(B,2),\"G\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Magnitude of earth's field is 0.32 G\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.4 Page no 434"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"a=60\n",
"a2=45\n",
"\n",
"#Calculation\n",
"import math\n",
"a1=math.tan(a2*3.14/180.0)/math.cos(a*3.14/180.0)\n",
"a3=math.atan(a1)*180/3.14\n",
"\n",
"#Result\n",
"print\"Apparent value of the dip is\", round(a3,1),\"degree\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Apparent value of the dip is 63.4 degree\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.6 Page no 434"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"l=30 #cm\n",
"l=0.15 #m\n",
"r=0.30 #m\n",
"Bh=0.34*10**-4 #T\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"M=Bh*(r**2-l**2)**2/(2*u*r)\n",
"m=M/(2*l)\n",
"\n",
"#Result\n",
"print\"Pole strength of the magnet is\",m,\"Am\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Pole strength of the magnet is 8.60625 Am\n"
]
}
],
"prompt_number": 16
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.7 Page no 434"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"M=0.4 #Am**2\n",
"r=0.1 #m\n",
"l=0.05 #m\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"Bh=u*M/((r**2+l**2)**1.5)\n",
"\n",
"#Result\n",
"print\"Horizontal component of earth's magnetic field is\", round(Bh*10**4,3)*10**-4,\"T\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Horizontal component of earth's magnetic field is 2.86e-05 T\n"
]
}
],
"prompt_number": 22
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.8 Page no 435"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"B=0.33\n",
"a=0\n",
"u=10**-7\n",
"I=2.5 #A\n",
"\n",
"#Calculation\n",
"import math\n",
"Bh=B/math.cos(a*3.14/180.0)\n",
"a=u*2*I/(Bh*10**-4)\n",
"\n",
"#Result\n",
"print\"Neutral point is\", round(a*10**2,1),\"cm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Neutral point is 1.5 cm\n"
]
}
],
"prompt_number": 28
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.9 Page no 435"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"Bh=0.32 #G\n",
"B=0.48 \n",
"\n",
"#Calculation\n",
"import math\n",
"a=B/Bh\n",
"a1=math.atan(a)*180/3.14\n",
"\n",
"#Result\n",
"print\"New stable equilibrium is\", round(a1,1),\"degree\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"New stable equilibrium is 56.3 degree\n"
]
}
],
"prompt_number": 32
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 4.10 Page no 435"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"n=22\n",
"a=0.1 #m\n",
"Bh=0.3*10**-4 #T\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"import math\n",
"K=2*a*Bh/(n*4*math.pi*u)\n",
"\n",
"#Result\n",
"print\"Reduction factor is\", round(K,3),\"A\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Reduction factor is 0.217 A\n"
]
}
],
"prompt_number": 36
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.11 Page no 435"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"n=40\n",
"a=0.12\n",
"I=0.15\n",
"a1=45 #degree\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"import math\n",
"Bh=(n*u*4*math.pi*I)/(2.0*a*math.tan(a1*3.14/180.0))\n",
"\n",
"#Result\n",
"print\"Strength of horizontal component is\", round(Bh*10**4,3),\"*10**-4 T\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Strength of horizontal component is 0.314 *10**-4 T\n"
]
}
],
"prompt_number": 51
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.12 Page no 435"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"a1=30\n",
"a2=45 #degree\n",
"\n",
"#Calculation\n",
"import math\n",
"n=2*math.tan(a1*3.14/180.0)/(math.tan(a2*3.14/180.0))\n",
"\n",
"#Result\n",
"print\"Ratio of number of turns is\", round(n,3)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ratio of number of turns is 1.155\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.13 Page no 436"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"n=16\n",
"a=0.1 #m\n",
"i=0.75 #A\n",
"Bh=5*10**-2 #T\n",
"v=2 #/s\n",
"\n",
"#Calculation\n",
"import math\n",
"M=n*i*math.pi*a**2\n",
"I=M*Bh/(4*math.pi**2*v**2)\n",
"\n",
"#Result\n",
"print\"Moment of inertia is\",round(I*10**4,3),\"*10**-4 Kg m**2\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Moment of inertia is 1.194 *10**-4 Kg m**2\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.14 Page no 436"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"T1=2.5\n",
"T2=4.5\n",
"M2=1.5\n",
"\n",
"#Calculation\n",
"M=T2**2/(M2*T1**2)\n",
"\n",
"#Result\n",
"print\"Ratio of magnetic moment is\",M"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ratio of magnetic moment is 2.16\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.15 Page no 436"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"T1=3.0\n",
"T2=4.0\n",
"\n",
"#Calculation\n",
"M=(T2**2+T1**2)/(T2**2-T1**2)\n",
"\n",
"#Result\n",
"print\"Ratio of magnetic moments is\",round(M,2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ratio of magnetic moments is 3.57\n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.16 Page no 436"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"a1=35 #Degree\n",
"B=0.39\n",
"I=1 #A\n",
"a=4.0*10**-2\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"import math\n",
"Bh=B*math.cos(a1*3.14/180.0)\n",
"Bv=B*math.sin(a1*3.14/180.0)\n",
"B1=(u*2*I*4/a)*10**4\n",
"Rh=Bh-B1\n",
"R=math.sqrt(Rh**2+Bv**2)\n",
"Rh1=Bh+B1\n",
"R3=math.sqrt(Rh1**2+Bv**2)\n",
"\n",
"#Result\n",
"print\"Resultant magnetic field is\", round(R3,3),\"G\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resultant magnetic field is 0.566 G\n"
]
}
],
"prompt_number": 39
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.17 Page no 436"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"M=5.25*10**-2 #J/T\n",
"Bh=0.42*10**-4 #T\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"r=(u*M/Bh)**0.333\n",
"r1=(u*2*M/Bh)**0.333\n",
"\n",
"#Result\n",
"print\"(a) Distance from the centre of the magnet on its normal bisector is\", round(r*10**2,1),\"cm\"\n",
"print\"(b) Distance from the centre of the magnet on its axis is\",round(r1*10**2,1),\"cm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a) Distance from the centre of the magnet on its normal bisector is 5.0 cm\n",
"(b) Distance from the centre of the magnet on its axis is 6.3 cm\n"
]
}
],
"prompt_number": 51
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.18 Page no 437"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given\n",
"I=0.35 #A\n",
"n=30\n",
"a=12.0*10**-2\n",
"u=10**-7\n",
"\n",
"#Calculation\n",
"import math\n",
"Bh=u*2*math.pi*n*I*0.707/a\n",
"\n",
"#Result\n",
"print\"(a) Horizontal component of the earth's magnetic field is\", round(Bh*10**4,2),\"G\"\n",
"print\"(b) The needle will reverse its original direction i.e. it will point east to west.\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a) Horizontal component of the earth's magnetic field is 0.39 G\n",
"(b) The needle will reverse its original direction i.e. it will point east to west.\n"
]
}
],
"prompt_number": 60
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.19 Page no 437"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#given\n",
"t1=9 #S\n",
"t2=4.5\n",
"Bh=0.34*10**-4 #T\n",
"u=10**-7\n",
"r=0.1 #m\n",
"\n",
"#Calculation\n",
"Baxial=Bh*((t1**2/t2**2)-1)\n",
"M2=Baxial*r**2/(2*u)\n",
"\n",
"#Result\n",
"print\"Magnetic moment is\", M2*10**-1,\"A m**2\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Magnetic moment is 0.51 A m**2\n"
]
}
],
"prompt_number": 66
}
],
"metadata": {}
}
]
}