Question

A capacitor is charged by using a battery which is then disconnected. A dielectric slab is then slipped between the plates, which results in

• A. Reduction of charge on the plates and increase of potential difference across the plates
• B. Increase in the potential difference across the plate, reduction in stored energy, but no change in the charge on the plates
• C. Decrease in the potential difference across the plates, reduction in the stored energy, but no change in the charge on the plates
• D. None of the above

Answer 1

The correct option is C

Decrease in the potential difference across the plates, reduction in the stored energy, but no change in the charge on the plates

Battery in disconnected so Q will be constant. So with introduction

of dielectric slab capacitance will increase and using Q = CV, V will decrease and

using , energy will decrease.