試題詳解

23. A square conductive loop of side L and resistance R is pulled with constant speed u out of a uniform magnetic field B. The magnetic feld is perpendicular to and pointing into the plane of the loop, as shown in the figure. Which of the following is correct?

(A) The induced EMF is BLu；
(B) The induced current is BLU/R；
(C)The force required to pull the loop is B²L²u/R；
(D) The power required to pull the loop is B²L²U²/R²；
(E) The direction of the electric current is clockwise.