試題詳解

48. A bar magnet approaches a conducting loop from the left with its north pole directed towards the loop. Considering the effect of electromagnetic induction, the induced current in the loop has the greatest magnitude and a clockwise direction ________.

(A) as the north pole of the magnet approaches the loop
(B) when the north pole has passed through the loop, but the south pole has not yet passed through
(C) when the north pole has passed through and the south pole is about to pass through the loop
(D) as the south pole of the magnet leaves the loop
(E) after the south pole of the magnet is several centimeters to the right of the loop