Question

A parallel plate capacitor is charged and then isolated. What is the effect of increasing the plate separation on charge, potential, capacitance, respectively?

• A. Constant, decreases, decreases
• B. Increases, decreases, decreases
• C. Constant, decreases, increases
• D. Constant, increases, decreases

Answer 1

Answer: (D)

Constant, increases, decreases

As the capacitor is isolated after charging, charge on it remains constant. Plate separation increases d, decreases $C={ϵ}_{0}A/d$ and hence increases potential $V=Q/C$.