Question

The amount of work done in increasing the voltage across the plates of a capacitor from $5V$to $10V$is W. The work done in increasing it from $10V$to $15V$will be

• A. 0.6 W
• B. W
• C. 1.25 W
• D. 1.67 W

Answer 1

Answer: (D)

1.67 W

Answer 2

As we know that work done $= U_{final} - U_{initial}$

$= \frac{1}{2}C(V_{2}^{2} - V_{1}^{2})$

When potential difference increases from $5V$to $10V$then

$W = \frac{1}{2}C(10^{2} - 5^{2})$ ……..(i)

When potential difference increases from $10V$to $15V$then

$W' = \frac{1}{2}C(15^{2} - 10^{2})$ ……..(ii)

On solving equation (i) and (ii) we get

$W' = 1.67W.$