試題詳解

35. Two flat 4.0cm ✖ 4.0cm electrodes carrying equal but opposite charges are spaced 2.0 mm apart with their midpoints opposite each other. Between the electrodes but not near their edges, the electric field strength is 10⁶ N/C. What is the magnitude of the xc= 100Q charge on each electrode? (ε₀ = 8.85✖10^-12 F/m)
(A) 4 nC
(B) 10 nC
(C) 14 nC
(D) 20 nC
(E) 24 nc