# A large magnet is broken into two pieces so their lengths are in the ratio 2:1.What will be ratio of their pole strengths ?

Dear Student,

The pole strength due to the magnetic charge qm at a distance r is given by

$\frac{{\mu }_{0}{q}_{m}}{4\pi {r}^{2}}$  (1)  Even though this equation is derived for a solenoid, the same results can
be applied to a bar magnet as both produce similar magnetic fields.

From equation (1) it can be observed that magnetic pole strength is independent of the
length of the bar magnet. Hence even after breaking the ratio of the magnets pole strength will be 1:1

Hope this clears the problem.