A dielectric slab is introduced between the plates of an isolated charged capacitor. Which of the following quantities remains unchanged?

Step-by-step solution

For an isolated charged capacitor, the battery is disconnected. Thus, the charge on the capacitor plates has no path to escape or increase, so it remains constant. When a dielectric slab of dielectric constant K is introduced, the capacitance increases from C to KC . Since charge Q is constant, the potential difference V = Q C becomes V' = Q KC = V K , which means it decreases. The electric field E = V d becomes E' = V' d = E K , which means it decreases. The stored energy U = Q^2 2C becomes U' = Q^2 2KC = U K , wh