試題詳解

4.When a fixed amount of ideal gas goes through an adiabatic expansion, A bar magnet is dropped from above and falls through the loop of wire shown below. The north pole of the bar magnet points downward towards the page as it falls. Which statement is correct?
(A) The current in the loop always flows in a counterclockwise direction.
(B) The current in the loop always flows in a clockwise direction.
(C) The current in the loop flows first in a clockwise, then in a counterclockwise direction.
(D) No current flows in the loop because both ends of the magnet move through the loop.
(E) The current in the loop flows first in a counterclockwise, then in a clockwise direction.