Gauss’ s Law in Magnetism
Surface integral of magnetic field over any closed or open surface is always m.
This law tells that the net magnetic flux through any surface is always zero.
[ When in an atom any electron revolve in an orbit it is equivalent to a current loop. Therefore, atom behaves as a magnetic dipole ].
Magnetic Moment of an Atom Magnetic moment of an atom M = 1 / 2 eωr 2 where e = charge on an electron, ω = angular velocity of electron and r = radius of orbit. or M = n eh / 4πm
where h = Planck’ s constant and m ~ mass of an electron and eh / 4πm = μ B, called Bohr magneton and its value is 9.27 * 10-24 A-m 2.
Earth’ s Magnetism Earth is a huge magnet. There are three components of earth’ s magnetism
( i) Magnetic Declination( θ) The smaller angle subtended between the magnetic meridian and geographic meridian is called magnetic declination.
( ii) Magnetic Inclination or Magnetic Dip( δ) The smaller angle sub tended between the magnetic axis and horizontal is called magnetic inclination on magnetic dip.