Physics - Capacitor Question with Solution | TestHub

Let's analyze each statement:

$E=\frac{Q}{{ϵ}_{0}A}$. Since $Q$ and $A$ are constant, $E$ remains unchanged. So, statement A is correct.

The potential energy stored in the capacitor is $U=\frac{Q^2}{2C}$. Since $Q$ is constant and $C$ decreases, $U$ increases. So, statement D is incorrect.

Statement B: Work done by an external force is positive because the plates attract each other, and pulling them apart requires work. So, statement B is incorrect.

Battery remains connected

$U=\frac{1}{2}C{V}^2$. Since $V$ is constant and $C$ decreases, $U$ decreases. So, statement C is correct.