Question

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 :-
(1) decreases by a factor of 2
(2) remains the same
(3) increases by a factor of 2
(4) increases by a factor of 4

Answer 1

(1) When battery is replaced by another uncharged capacitor

U_f = 1/2  U_i
i.e., Total electrostatic energy of resulting system decreases by a factor of 2