Question 7 of 9intermediate🔧 ApplyNumerical3 marks
A bar magnet of magnetic moment 1.5 J T –1 lies aligned with the direction of a uniform magnetic field of 0.22 T. (a) What is the amount of work required by an external torque to turn the magnet so as to align its magnetic moment: (i) normal to the field direction, (ii) opposite to the field direction? (b) What is the torque on the magnet in cases (i) and (ii)?
(a)
(b)
Explanation
This question tests understanding of potential energy and torque on a magnetic dipole in a uniform magnetic field. The potential energy is U = -mB cosθ, and work done equals change in potential energy. Torque is given by τ = mB sinθ.