The drawing shows a bar magnet falling through a metal ring. In part a the ring is

Question:

The drawing shows a bar magnet falling through a metal ring. In part a the ring is solid all the way around, but in part b it has been cut through.
(a) Explain why the motion of the magnet in part a is retarded when the magnet is above the ring and below the ring as well. Draw any induced currents that appear in the ring.
(b) Explain why the motion of the magnet is unaffected by the ring in part b.