Question

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

• A. increase in the potential difference across the plates and reduction in stored energy but no change in the charge on the plates
• B. decrease in the potential difference across the plates and reduction in the stored energy but no change in the charge on the plates
• C. reduction of charge on the plates and Increase of potential difference across the plates
• D. increase in stored energy but no change in potential difference across the plates

Answer 1

The correct option is B decrease in the potential difference across the plates and reduction in the stored energy but no change in the charge on the plates

If a dielectric slab of dielectric constant K is filled in between the plates of a capacitor after charging the capacitor (i.e., after removing the connection of battery with the plates of capacitor) the potential difference between the plates reduces to $\frac{1}{K}$ times and the potential energy of capacitor reduces to $\frac{1}{K}$ .times but there is no change in the charge on the plates.