試題詳解

39.A flat coil of wire consisting of 20 turns, each with an area of 50 cm², is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 2.0 T to 6.0 T in 2.0 s. If the coil has a total resistance of 0.40 Ω, what is the magnitude of the induced current?
(A) 0.2 A
(B) 0.5 A
(C) 0.7 A
(D) 0.9 A
(E) 1.0 A