Lines which represent places of constant angle of dip are called

In the magnetic meridian of a certain place,the horizontal component of the earth's magnetic field is $0.26 \ G$ and the dip angle is $60^{\circ}$. What is the magnetic field of the earth at this location (in $G$)?

The angle of dip is $90^{\circ}$ at:

The magnetic field due to the Earth is closely equivalent to that due to:

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

Explain geographic meridian and magnetic meridian.