At the magnetic poles of the earth,a compass needle will be

If a magnet is suspended freely such that it can rotate about its magnetic axis,in which plane does it come to rest?

What was the early recognition of Earth's magnetic field? State the dynamo effect.

Lines which represent places of constant angle of dip are called

$A$ magnetic compass needle oscillates $30$ times per minute at a place where the angle of dip is $45^{\circ}$,and $40$ times per minute where the angle of dip is $30^{\circ}$. If $B_1$ and $B_2$ are respectively the total magnetic field due to the earth at the two places,then the ratio $B_1/B_2$ is best given by:

The angles of dip are $30^{\circ}$ and $45^{\circ}$ at two different places. The ratio of the horizontal components of the Earth's magnetic field at these places will be: