Energy of a charged capacitor is U. Now it is removed from a battery and then is connectec to another identical uncharged capacitor it parallel. What will be the energy of eacl capacitor now ?

Options

A. `(U)/(4)`
B. U
C. `(3U)/(2)`
D. `(U)/(2)`

Answer

D

Explanation

Suppose Q is the charge on the capacitor, so energy stored in the capacitor, U `= (Q^(2))/(2C)` .......... (1)
When another similar charge-less capacitor is connected with it, the charge on each capacitor becomes `(Q)/(2)` .
Hence energy of these both
`U_(1) =U_(2)`
`=((Q//2)^(2))/(2C)=(Q^(2))/(4xx2C)`
From equation (1)
`:. U_(1) = U_(2) = (U)/(4)`