Question

A positive charge is placed some distance in the -\hat{i} direction from the magnet. (Intro 1 figure) Assume that no charges are induced on the magnet.

Assume that the length of the magnet is much smaller than the separation between it and the charge. As a result of magnetic interaction (i.e., ignore pure Coulomb forces) between the charge and the bar magnet, the magnet will experience which of the following?

a) No torque at all b) A torque only if one magnetic pole is slightly closer to the charge than the other
c) A torque due to the charge attracting the south pole of the magnet d) A torque due to the charge attracting the north pole of the manget

Answer 1

a) No torque at all No magnetic field is produced by a static charge. Only a moving charge can produce a magnetic effect.And the magnet can not have any torque due to its own magnetic lines of force.