A parallel-plate capacitor is first charged to a certain charge and then isolated…
PHYSICS · Multi-part · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
A parallel-plate capacitor is first charged to a certain charge Q and then isolated from the charging source. A solid dielectric slab of relative permittivity κ>1 is now gently and completely inserted between the plates without touching them.
(i) Explain qualitatively how the potential difference across the plates changes after the insertion.
(ii) Explain how the electrostatic energy stored in the capacitor changes in this situation.
(iii) How would your answers to parts (i) and (ii) differ if the capacitor, instead of being isolated, remained connected to the same battery throughout the process? Justify your reasoning in each case.