1. An imaginary line (XY) passing through the magnetic north pole and magnetic south pole of a bar magnet is called its magnetic axis.
2. The distance (NS) between the north pole and south pole of a magnet is called the length or effective length of the magnet.
3. An imaginary line (PQ) bisecting the effective length of a magnet is called the magnetic equator of the magnet.
4. The region around a magnet where its magnetic force can be experienced is called the magnetic field.