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

Options

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

Answer

D

Explanation

Work done `(W)=(1)/(2)C(V_(2)^(2)-V_(1)^(2))`
`=(C)/(2)[10^(2)-5^(2)]=(75C)/(2)` . . . (1)
In the second case, `W'=(1)/(2)C[15^(2)-10^(2)]`
`=(C)/(2)[225-100]`
`=(125C)/(2)` . . (2)
`therefore (W')/(W)=(125C)/(2)xx(2)/(75C)=(5)/(3)=1.67`
`therefore W'=(1.67)W`