The magnetic moment of a magnet is defined as the product of the pole strength and the distance between the two poles.
The magnetic moment (or magnetic dipole moment) of an object is a measure of the object’s tendency to align with a magnetic field. There are two sources for a magnetic moment: the motion of electric charge and spin angular momentum. Since any magnet has two poles, it is also called a magnetic dipole.
If m is the pole strength of each pole and 2Ɩ is the distance between the poles, the magnetic moment,
Ḿ = m (2Ɩ)
Magnetic moment is a vector quantity. It is denoted by M. Its unit is A m2. Its direction is from South Pole to North Pole.