A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system:

Options

A. Decreases by a factor of `2`
B. Remains the same
C. Increases by a factor of `2`
D. Increases by a factor of `4`

Answer

A

Explanation

`U_(i)=1/2CV^(2)`
`V'=(CV+0)/(C+C)=V/2`
`U_(f)=1/2(C+C)(V/2)^(2)=1/4CV^(2)`
`(U_(f))/(U_(i))=1/2`