Question

Work done in rotating a bar magnet from 0 to angle 120 is​

Answer 1

Answer:

3/2 M B

Explanation:

Word done= Final P.E - Initial P.E

So we have,

P.E = -M B ( cosθ₂- cosθ₁)    M stands for Magnetic moment

                                             B stands for Magnetic induction

Word done= -M B cos 120°- (-M B cos0°)          [cos 120°= - 1/2 and cos 0°= 1]

                    = 1/2M B + M B

                     = 3/2 M B