Question

A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and work done by the battery will be 

(A) (1/2) 

(B) (2/1) 

(C) 1 

(D) (1/4)

Answer 1

The correct option (A) (1/2)

Explanation:

Work done = W = QV

as Q = CV hence W = CV²

Energy stored in capacitor C is (1/2)CV²

∴ [(Energy stored in capacitor)/(Work done by capacitor)]

= [{(1/2)CV²}/(CV²)] = (1/2)