Question

$1000$ small water drops each of radius $r$ and charge $q$ coalesce to form one spherical drop. The potential of big drop is larger than that of smaller ones by a factor

• A. $1000$
• B. $100$
• C. $10$
• D. $1$

Answer 1

The correct option is B $100$

Let V be potential of small drop and q be the charge of the drop.
$v=\frac{kq}{R.}$

New radius of lirg drop$=(1000{)}^{{}^1{/}_3}R$ (volume must be equal)
$R_1=10R$

We know thet: $V_1=\frac{k\left(1000.q\right)}{10R}$
$V_1=100\frac{kq}{R}$
$V_1=100v$