A magnet of length 10 cm and pole strength 4×10−4 A.m is placed in a magnetic field of induction 2×10−5 Wb−m−2, such that the axis of the magnet makes an angle 30o with the lines of induction. The moment of the couple acting on the magnet is
A bar magnet of length 10 cm and pole strength 2 Am makes an angle 60o with a uniform magnetic field of induction 50T. The couple acting on it :