Question

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

Answer 1

Answer: (B)

A, C and E only

Answer 2

When the plates of a parallel plate capacitor connected to a battery are moved closer:
$\bullet$ The capacitance $C$ of the capacitor increases because $C = \frac{\epsilon_0 A}{d}$, where $d$ is the separation between the plates, and $d$ decreases.
$\bullet$ Since the capacitor is connected to a battery, the voltage $V$ remains constant. The increased capacitance leads to an increase in the charge $Q = CV$.
$\bullet$ The product of charge and voltage, $Q \cdot V$, increases as the charge $Q$ increases.
Thus, statements A, C, and E are correct.