Several spherical deops of a liquid each of radius r coalesece to from 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^(3)T((1)/(r)-(1)/(R))`
C. `(4)/(3)pir^(2)T((1)/(r)-(1)/(R))`
D. `2piRT((1)/(R)-(1)/(r))`

Answer

A

Explanation

`n((4)/(3)pir^(3))=4/3piR^(3)`
`{:(R=n^(1//3)r),(U_(1)=nT4pir^(2)),(U_(1)=T4piR^(2)),(U_(2)=T4piR^(2)),(W=U_(1)-U_(2)):}`
`W=T4piR^(2)" "{n^(1//3)-1}`
`W=T4piR^(3){(1)/(r)-(1)/(F)}`