WAEC Physics 2020 Paper

Concept:When the battery is disconnected, the charge on the capacitor remains fixed.Explanation:The capacitance of a parallel plate capacitor is given by:$$C = \frac{\varepsilon_0 A}{d}$$Here, $A$ is the plate area and $d$ is the separation between the plates.Moving the plates farther apart increases $d$.Since $C$ is inversely proportional to $d$, increasing $d$ causes $C$ to decrease.Because the battery is disconnected, the charge $Q$ stored on the plates stays constant.Therefore, only the capacitance changes, and it decreases.Answer:B. capacitance would decrease