試題詳解

40. A parallel-plate capacitor without dielectrics is charged with +Q₀ and -Q₀ on their two metal
plates, and the charging battery is disconnected. When a dielectric layer with a dielectric constant k (k ≥ 1) is inserted to fill the gap between the two metal plates, what is the bound charge on the surface of the dielectric layer in contact with the metal plate?
(A) Q₀(k − 1)/k
(B) (k − 1)Q₀
(C) (2 − k)Q₀
(D) kQ₀/(k − 1)
(E) Q₀/(k + 1)