Question

Earth's Magnetic Field —

Answer 1

Earth's Magnetic Field —

Earth has a magnetic field associated with it that behaves approximately similar to that of a magnetic dipole. A freely suspended magnet always point in the north-south direction even in the absence of any other magnet. This suggests that the earth itself behaves as a magnet.

The south pole of a earth's magnet is towards the earth's north pole (geographical north), while the north pole of earth's magnet is towards earth's south pole (geographical south). Thus, there is a magnetic $S$-pole near the geographical north and a magnetic $N$-pole near the geographical south. The positions of the earth's magnetic poles are not well defined on the globe, they are spread over an area.

Magnetic Equator : The great circle whose plane is perpendicular to the earth's magnetic axis is called earth's magnetic equator.

Geographical Equator : The great circle whose plane is perpendicular to geographical axis is called geographical equator.

Magnetic Meridian : The line joining the earth's magnetic poles is called the magnetic axis and a vertical plane passing through it is called the magnetic meridian.

Geographical Meridian : The line joining the geographical north and south poles is called the geographical axis and a vertical plane passing through it is called the geographical meridian.