Question

Two identical parallel plate capacitors A and B(parallel)are connected to a batteryof

V volts with the switch S closed. The switch is now opened and the free

space between the plates of the capacitors is filled with a dielectric of

dielectric constant K. Find the ratio of the total electrostatic energy stored

in both capacitors before and after the introduction of the

dielectric.

Answer 1

Answer = k/1 not 1/k we have to take charge constant because switch is off so no current will flow and charge will not change.