(N/A) The pole strength of a bar magnet is a measure of the force that a magnetic pole exerts on other magnetic poles.
It is denoted by $q_{m}$ or $P$.
Pole strength is a scalar quantity,and its $SI$ unit is ampere-meter $(Am)$.
It depends on the material of the magnet,its magnetization,and its cross-sectional area $(A)$.
If the length of a bar magnet is $(2l)$ and its pole strength is $q_{m}$,then the magnetic dipole moment $\vec{m}$ is defined as the product of the pole strength and the magnetic length:
$\vec{m} = q_{m} \times (2\vec{l})$
The direction of the magnetic dipole moment $\vec{m}$ is from the South pole $(S)$ to the North pole $(N)$.
This is analogous to the electric dipole moment $\vec{p} = q(2\vec{a})$ in electrostatics,where pole strength $q_{m}$ corresponds to electric charge $q$ and magnetic length $(2l)$ corresponds to the separation distance $(2a)$.