question_answer

Two mercury drops (each of radius' r') merge to from bigger drop. The surface energy of the bigger drop, if T is the surface tension, is:                                                                                                          [AIEEE 11-05-2011]

A) \[4\eta {{r}^{2}}T\]     

B)      \[2\eta {{r}^{2}}T\]

C) \[{{2}^{8/3}}\eta {{r}^{2}}T\]          

D)      \[{{2}^{5/3}}\eta {{r}^{2}}T\] 

Correct Answer: C

Solution :

[c]