Question

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

Answer 1

Correct Answer - C
Final surface energy `= 1000 xx 4 pi r^(2) sigma`
Initial surface energy, `E = 4 pi R^(2) sigma`
Again, `(4)/(3) pi R^(3) = 1000 xx (4)/(3) pi r^(2)`
or `R = 10 r`
Now, final energy
`1000 xx 4 pi r^(2) sigma = 10 xx 4 pi R^(2) sigma = 10 E`.