試題詳解

39. The electric potential in an xy plane is given byV . What is the magnitude of the electric field at the point (3.0 m, 2.0 m)?
(A) 5.0 N /C
(B) 6.0 N /C
(C) 8.0 N /C
(D) 10 N /C
(E) 14 N /C