The surface energy of a liquid drop is `E`. It is sprayed into `1000` equal droplets.
the work done in spraying is:

Options

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

Answer

B

Explanation

Let r be the radius of smaller drops and R the radius of bigger drop. Then by equating volume, we have
`1000((4)/(3)pi r^(3))=(4)/(3) pi R^(3) " or" r=(R )/(10)`
Surface energy `prop` surface area
`S_(i)=4pi R^(2) " or" S_(f)=1000(4 pi r^(2))=10(4 pi R^(2))=10 S_(i)`
As surface area has increased 10 times, surface energy will also become ten times.