Question

A battery does 200 J of work in charging a capacitor. The energy stored in the capacitor is

• A. $200J$
• B. $100j$
• C. $50J$
• D. $400J$

Answer 1

Answer: (B)

$100j$

Given,

$W_B=200J$

If we charge a capacitor by battery, then the energy stored in the capacitor will be equal to half of the work done by the battery.

The work done by the battery, $W_B=qV$

The energy stored in the capacitor will be,

$E_C=\frac{1}{2}qV=\frac{200}{2}$

$E_C=100J$

The correct option is B.