Question

Twenty seven spherical drops, each of radius 3mm and carrying 10^–12C of charge are combined to form a single drop. Find the capacitance and potential of the bigger drop.

Answer 1

 Let r and R be the radii of smaller and bigger drops respectively. 

Volume of bigger drop = 27 x Volume of smaller drop

Since charge is conserved, the charge on the bigger drop is 27 × 10^–12 C.

∴ Potential of bigger drop,