A mercury drop of water has potential 'V' on its surface. 1000 such drops combine to form a new drop. Find the potential on the surface of the new drop.

Options

A. V
B. 10V
C. 100V
D. 1000V

Answer

C

Explanation

Let the radius of each mercury drop be r.
If q is charge on each drop
The potential of drop `V=q/(4piin_(0)r)` or `q=4piin_(0)r V....(1)`
Let R be the radius of the new drop formed by combination of 1000 drops of radius r.
`(4pi)/3R^(3)=1000(4pi)/3 r^(3) rArr R=10 r` .....(2)
`:.` Potential of new drop `((1000q))/(4pi in_(0)R)=((100q))/(4piin_(0)r)=100 V`