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 ?

The diagrams below show regions of equipotentials. A positive charge is moved from A to B in each diagram.

Suppose the charge of a proton and an electron differ slightly. One of them is - e, the other is (e + ∆e). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then ∆e is of the order of [Given mass of hydrogen mh = 1.67 × 10−27 kg ] ?