試題詳解

17.Consider a parallel-plate capacitor of plate area A and plate separation. A potential difference Vo is applied between the plates. The battery is then disconnected, and a dielectric slab of thickness b and dielectric constant k is placed between the plates. Assuming A 100cm² , d 1.00cm, Vo 90V, b 0.8cm, k 2.00. What is the capacitance with the slab in place? ( )
(A)14.8pF
(B)16.8pF
(C)17.9pF
(D)20.9pF
(E)21.9pF