Question

Energy of a charged capacitor is U. Now it is removed from a battery and then is connected to another identical uncharged capacitor in parallel. What will be the energy of each capacitor now ?(A) 3U/2
(B) U
(C) U/4
(D) U/2

Answer 1

Answer:

(C) U/4

Explanation:

Energy of a charged capacitor = U

Let the charge on capacitor be = Q.

Thus, the energy Stored : Q²/2C

The flow of charge will be such that the potential difference and total charge (Q) across the capacitor remains same.

Hence,

Potential difference across the capacitor-

V = Q/2C

Energy in each capacitor -  1/2C V²

= 1/2C × (Q/2C)²

= 1/4 × (1/2 Q²/C)

= 1/4U

Therefore, the energy of each capacitor will be U/4 .