問題詳情

12. A loop of wire locates at the upper side of a long wire carrying currents of 5A. When the loop falls down toward the wire at the speed ofy, what is the direction of force exerted on the loop by the long wire at this moment?


(A) upward,
(B) downward,
(C) left,
(D) right,
(E) impossible to determine.

參考答案

答案：A
難度：計算中-1
書單：沒有書單，新增