Question

The surface energy of a liquid drop is `E`. It is sprayed into `1000` equal droplets. Then its surface energy becomes
A. u
B. 10 u
C. 100 u
D. 1000 u

Answer 1

Correct Answer - B
Given, `u = S xx 4pi R^(2)`, when droplet is splitted into 1000 droplets each of radius r, then
`(4)/(3) pi R^(3) = 1000 xx (4)/(3) pi r^(3) rArr r = R//10`
`:.` Surface energy of all droplets `= S xx 1000 xx 4pi r^(2)`
`= S xx 1000 xx 4pi (R//10)^(2) = 10(S xx 4pi R^(2)) = 10 u`