The surface energy of a liquid drop is $U$. It splits up into $512$ equal droplets. The surface energy becomes (in $U$)

$A$ soap bubble of radius $\frac{1}{\sqrt{\pi}} \text{ cm}$ is expanded to radius $\frac{3}{\sqrt{\pi}} \text{ cm}$. The surface tension of the soap solution is $25 \text{ dyne/cm}$. The work done during expansion in $\text{erg}$ is:

What will be the work done in increasing the radius of a soap bubble from $\frac{r}{2}$ to $2r$, if the surface tension of the soap solution is $T$ (in $\pi r^2 T$)?

Two small droplets combine to form a single large drop. What is the ratio of the surface energy of the small droplets to the surface energy of the large drop?

The potential energy of a molecule on the surface of a liquid compared to the molecules inside the liquid is:

The work done in blowing a soap bubble of radius $0.2\, m$ is (the surface tension of soap solution being $0.06\, N/m$).