A pendulum carries at its end a solid rectangular copper plate
PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A pendulum carries at its end a solid rectangular copper plate. The plate is replaced by an identical copper plate having several narrow radial slots cut right through it. Which statement correctly describes the change, if any, in the motion?
(a) The slotted plate shows greater damping because its higher electrical resistance causes larger energy loss as heat.
(b) The slotted plate shows noticeably less damping because the slots break the paths of circulating eddy currents.
(c) Both plates exhibit the same damping because the drag depends only on the surface area moving through air.
(d) The solid plate shows less damping because its larger mass makes it harder to retard the motion.