The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism. Why ?

Temperature of earth increasing. Why?

The charged currents in the outer conducting regions of the earth's core are thought to be responsible for earth's magnetism. What might be the 'battery' (i.e., the source of energy) to sustain these currents ?

A magnetic needle free to rotate in a vertical plane parallel to the magnetic meridian has its north tip pointing down at 22^(@) with the horizontal. The horizontal component of the earth's magnetic field at the place is known to be 0.35 G. Determine the magnitude of the earth's magnetic field at the place.

what is the percentage of sources of water on earth ?

In the magnetic meridian of a certain place the vertical component of the earth's magnetic field is 0.3464 G and the dip angle is 30^(@) . The horizontal component of the earth 's magnetic field at this location is

A short bar magnet of magnetic moment 0,21 A - m^(2) is placed with its axis perpendicular to the direction of the horizontal component of the earth 's magnetic field .The distance of the point on the axis of the magnet from the centre of the magnet where the resultant magnetic field is inclined at 45^(@) with the horizontal component of the earth's field direction is (horizontal component of the earth's magnetic field 4.2xx10^(-5)