Several spherical drops of a liquid each of radius r coalesce to form a single drop of radius R. If T is the surface tension, then the energy liberated will be -

Options

A. `4piR^(3)T((1)/(r)-(1)/(R))`
B. `2piR^()T((1)/(r)-(1)/(R))`
C. `(4)/(3)piR^(2)T((1)/(r)-(1)/(R))`
D. `2piRT((1)/(R)-(1)/(r))`

Answer

A

Explanation

Energy liberated `=T(A_(1)-A_(2))`
`=T(n4pir^(2)-4piR^(2)) and (nr^(3)=R^(3))`