Question

A charge of $10^{- 9}C$ is placed on each of the 64 identical drops of radius $2cm$. They are then combined to form a bigger drop. Find its potential

• A. $7.2 \times 10^{3}V$
• B. $7.2 \times 10^{2}V$
• C. $1.44 \times 10^{2}V$
• D. $1.44 \times 10^{3}V$

Answer 1

Answer: (A)

$7.2 \times 10^{3}V$

Answer 2

$V = n^{2/3}v$ ⇒ $V = (64)^{2/3} \times 9 \times 10^{9} \times \frac{10^{- 9}}{(2 \times 10^{- 2})}$= 7.2 × 10³ V