學士後西醫-物理題庫下載題庫

41. As shown in the figure, point charges q and Q are positioned as shown. Ifq = +2.0 nC, Q = -2.0 nC, a = 3.0 m, and b = 4.0 m, what is the electric potential difference, V_A - V_B?
(A) 2.4V
(B) 4.8V
(C) 6.0V
(D) 7.2V
(E) 8.4V