2024 Electrostatic Potential and CapacitanceParallel Plate Capacitor connected to a Battery Medium Question 11 of 76 in Electrostatic Potential and Capacitance

If the plates of a parallel plate capacitor connected to a battery are moved close to each other, then A. the charge stored in it, increases. B. the energy stored in it, decreases. C. its capacitance increases. D. the ratio of charge to its potential remains the same. E. the product of charge and voltage increases. Choose the most appropriate answer from the options given below:

A B, D and E only
B A, B and C only
C A, B and E only
D A, C and E only

The answer is D.

Solution

$C = \frac{\varepsilon_0 A}{d}$; as d decreases, C increases (C true). The battery remains connected, so V = constant. $q = CV \propto C$, so the charge increases (A true). Energy stored $U = \frac{1}{2}CV^2$ increases as C increases, so B ('energy decreases') is false. $\frac{q}{V} = C$ increases, so D is false. $qV = CV^2$ also increases (E true). So A, C and E only are correct.

Concept Effect of plate separation on charge, capacitance and energy

Electrostatic Potential and Capacitance in past papers

76 questions from this chapter have appeared across 27 exam years.