Two insulated metallic spheres of `3mu F` and `5 muF` capacitances are charged to `300 V` and `500 V` respectively. The energy loss, when they are connected by a wire is

Options

A. `0.012 J`
B. `0.0218 J`
C. `0.0375 J`
D. `3.75 J`

Answer

C

Explanation

`DeltaU = (1)/(2) (C_(1)C_(2)(V_(2) - V_(1)^(2)))/((C_(1) + C_(2)))`
`= ((3 xx 5) xx 10^(-12) xx (500 - 300)^(2))/((3 + 5) xx 10^(-6))`
`= (15 xx 10^(-12) xx 4 xx 10^(4))/(8xx 10^(-6)) = 0.0375 J`