Capacitance is increased by increasing plate area and decreasing by increasing plate separation. Which statement is correct?

• A. Capacitance increases with larger plate area and decreases with greater plate separation.
• B. Capacitance decreases as plate area increases.
• C. Capacitance is independent of plate separation.
• D. Capacitance increases with distance between plates.

Answer: (A)

Capacitance depends on the geometry of the plates and the medium between them. For a parallel-plate capacitor, the relationship is C = ε A / d, where ε is the permittivity of the medium, A is the plate area, and d is the separation between the plates. This means that increasing plate area provides more surface to store charge at the same voltage, so C increases. Increasing the distance between plates reduces the coupling and lowers the charge that can be stored for the same voltage, so C decreases. The statement aligns with this: capacitance grows with larger area and shrinks with greater separation. The other ideas contradict C ∝ A/d, so they don’t fit.