The radius of a soap bubble is increased from $R$ to $2R$. The work done in this process in terms of surface tension $S$ is: (in $\pi R^2 S$)

Which of the following statements are true when two water drops coalesce to form a bigger drop?

The excess pressure in a soap bubble is double that in another one. The ratio of their volumes is .............

$A$ liquid drop of diameter $D$ breaks into $27$ small drops of equal size. If the surface tension of the liquid is $\sigma$,then the change in surface energy is

$A$ water drop is divided into $8$ equal droplets. The pressure difference between the inner and outer side of the big drop will be

$A$ spherical liquid drop splits into $729$ identical spherical drops. If $E$ is the surface energy of the original drop and $U$ is the total surface energy of the resulting drops,then $\frac{E}{U} = \frac{1}{x}$. The value of $x$ is