Question

identical drops are charged at 22 V each. They combine to form a bigger drop. The potential of the bigger drop will be ______ V .

Answer 1

Let the charge on one drop is q and its radius is r.

So for one drop

$V=\frac{Kq}{r}$

For 27 drops merged new charge will be Q = 27 q

and new radius is R = 3 r

So new potential is

$V'=\frac{kq}{R}=9\frac{kg}{r}=9×22 V$

= 198 V