Question: Two merucry drops (each of radius ' $r$ ') merge to form a bigger drop. The surface energy of the bigger drop, ifs $\mathrm{T}$ is the surface tension, is :
$2^{5 / 3} \pi r^{2} \mathrm{~T}$
$4 \pi \mathrm{r}^{2} \mathrm{~T}$
$2 \pi r^{2} T$
$2^{8 / 3} \pi r^{2} \mathrm{~T}$
Correct Option: , 4
Solution:
