A parallel plate capacitor is fully charged using a battery. The battery is then disconnected, and a dielectric slab is completely inserted between the plates. Which of the following statements are correct? A. The charge on the capacitor remains constant. B. The capacitance of the system decreases. C. The potential difference between the plates decreases. D. The electrostatic energy stored in the capacitor increases.

Step-by-step solution

When the battery is disconnected, the charge on the capacitor has no path to flow, so the charge remains constant: Q = Q₀ . (Statement A is correct) When a dielectric slab of dielectric constant K > 1 is inserted, the capacitance increases: C = K C₀ . (Statement B is incorrect) The potential difference is given by V = Q C = Q₀ K C₀ = V₀ K . Since K > 1 , the potential difference decreases. (Statement C is correct) The electrostatic energy stored is U = Q^2 2C = Q₀^2 2 K C₀ = U₀ K . Since K > 1 , the energy decrease