Physics > Magnetism and Matter > 7.0 Earth’s Magnetism
Magnetism and Matter
1.0 Introduction
2.0 Coulomb’s Law
3.0 Magnetic Dipole
3.1 Magnetic Dipole Moment
3.2 Magnetic Field Due to a Magnetic Dipole
3.3 Torque Acting on a Magnetic Dipole
3.4 Potential Energy of a Magnetic Dipole in a Uniform Magnetic Field
4.0 Current Carrying Loop
5.0 Gauss’s Law in Magnetism
6.0 Magnetic Moment of an Atom
7.0 Earth’s Magnetism
8.0 Tangent Law
9.0 Deflection Magnetometer
10.0 Vibration Magnetometer
11.0 Magnetic Flux
12.0 Magnetic Induction
13.0 Magnetic of Material
14.0 Classification of Magnetic Materials
15.0 Curie Law in Magnetism
16.0 Hysteresis
17.0 Retentivity or Residual Magnetism
18.0 Coercivity
19.0 Permanent Magnets
20.0 Electromagnets
21.0 Important Points
7.1 Some important terms
3.2 Magnetic Field Due to a Magnetic Dipole
3.3 Torque Acting on a Magnetic Dipole
3.4 Potential Energy of a Magnetic Dipole in a Uniform Magnetic Field
Magnetic Meridian
A vertical plane passing through the magnetic axis is called magnetic meridian.
Geographic Meridian
A vertical plane passing through the geographic axis is called geographic meridian.
Magnetic Map
Magnetic map is obtained by drawing lines on the surface of earth. which passes through different places having same magnetic elements. The main lines drawn on earth’s surface are $g1$ en below
(i) Isogonic Line A line joining places of equal declination is called on isogonic line.
(ii) Agonic Line A line joining places of zero declination is called an agonic line
(iii) Isoclinic Line A line joining places of equal inclination or dip is called an aclinic line,
(iv) Aclinic Line A hne joining places of zero inclination or dip is called an aclinic line.
(v) Isodynamic Line A line joining places of equal horizontal component of earth’s magnetic field $(H)$ is called an isodynamic line.
Magnetic Latitude
(i) If at any place, the angle of dip is $?$ and magnetic latitude is $?$ then tan $? = 2$ tan $?$
(ii) The total Intensity of earth’s magnetic field $$I = {I_0}\sqrt 1 + 3{\sin ^2}\lambda $$ Where, $${I_0} = \frac{M}{{{R^3}}}$$ It is assumed that a bar magnet of earth has magnetic moment M and radius of earth is $R.$ $($Magnetic maps are maps obtained by drawing lines passing through different places on the surface of earth, having the same value of a magnetic element.$)$
