If two droplets happen to combine into a single larger droplet, the new potential V at the surface

Question

A cloud contains spherical drops of water of radius R and charge Q. Assume the drops are far apart.

If two droplets happen to combine into a single larger droplet, the new potential V at the surface of the larger droplet is most nearly equal to

(A) 3V0

(B) 2V0

(C) 2/3√2 V0

(D) 3√2 V0

(E) V0

Answer 1

The correct option is: (C) 2/3√2 V0

Explanation:

Combining two droplets doubles the charge. The volume is doubled, which means the radius is multiplied by 3√2. This gives V = kQ/r = k(2Q)/(3√2r)