A straight wire CD of length 0.40 m is hinged at point C so that it can rotate freely in its own plane. The wire carries a current of 5 A and is situated in a horizontal uniform magnetic field of 0.3 T directed due north.
The wire is initially held so that it points due east and is then released.
Answer the following questions:
(i) Show that the wire experiences its maximum possible magnetic force immediately after it is released. State the direction of this force.
(ii) Explain why the magnetic force on the wire gradually decreases as it rotates, becoming zero at a certain orientation. Identify that orientation with respect to the magnetic field.
(iii) Calculate the torque acting on the wire about point C just after it is released and comment on how this torque changes as the wire rotates from the initial position to the position found in part (ii).