The amount of work done in increasing voltage across the plates of capacitor from 5 V to 10 V is W. The work done in increasing it from 10 V to 20 V is

Step-by-step solution

The work done in increasing the voltage across a capacitor is equal to the change in its electrostatic potential energy. W = U = 1 2 C (V_f^2 - V_i^2) For the first case, the voltage increases from 5 V to 10 V: W = 1 2 C (10^2 - 5^2) = 1 2 C (100 - 25) = 75 2 C For the second case, the voltage increases from 10 V to 20 V: W' = 1 2 C (20^2 - 10^2) = 1 2 C (400 - 100) = 300 2 C Taking the ratio of the two work done values: W' W = 300 75 = 4 W' = 4W Answer: 4W