Q.

A big drop is formed by coalescing 1000 small droplets of water. The ratio of surface energy of 1000 droplets to that of the energy of the big drop is 10x. The value of x is ____.            [2024]


Ans.

(1)

100043πr3=43πR3    R=10r

Surface energy of 1000 drops =1000×T×4πr2

Surface energy of bigger drop =T×4πR2

S.E. of 1000 dropsS.E. of Big drop=1000(4πr2)T4πR2T=1000×r2(10r)2

S.E. of 1000 dropsS.E. of Big drop=10=10x

 x=1