A parallel plate condenser with oil between the plates (dielectric constant of oil $k=2$ ) has a cap

Question

A parallel plate condenser with oil between the plates (dielectric constant of oil $k=2$ ) has a capacitance $C$. If the oil is removed, then capacitance of the capacitor becomes

Professor PC Thomas Classes · Answer

Capacitance $C \propto k$. If dielectric is removed, $C' = C/k = C/2$.