複選題

29.An air-filled parallel-plate capacitor is connected to a battery and allowed to charge up. Now a slab of dielectric material is placed between the plates while the capacitor is still connected to the battery. After that, one would find
(A) the charge on the capacitor had not changed.
(B) the energy stored in the capacitor had increased.
(C) the voltage across the capacitor had not changed.
(D) the charge on the capacitor had increased.
(E) None of these is true.