5.6 If the solenoid in Exercise 5.5 is free to turn about the vertical direction and a uniform horizontal magnetic field of 0.25 T is applied, what is the magnitude of torque on the solenoid when its axis makes an angle of 30° with the direction of applied field?

Magnetic field strength, B=0.25 T
Magnetic moment, M=0.6 T-1
The angle θ, between the axis of the solenoid and the direction of the applied field is 30°
Therefore, the torque acting on the solenoid is given as:
τ=MBsinθ=0.6×0.25sin30=7.5×102J