試題詳解

39. A square loop (L = 0.20 m) consists of 50 closely wrapped turns, each carrying a current of 0.50 A. The loop is oriented as shown in a uniform magnetic field of 0.40 T directed in the positive y 

direction. What is the magnitude of the torque on the loop?
(A) 0.21 Nㆍm
(B) 0.20 N ㆍm
(C) 0.35Nㆍm
(D) 0.12 N ㆍm
(E) 1.73 N ㆍm