The work done in blowing a soap bubble of radius $R$ is $W_1$ and that of radius $2R$ is $W_2$. The ratio of $W_1$ to $W_2$ is

$A$ mercury drop of radius $10^{-3} \ m$ is broken into $125$ equal size droplets. Surface tension of mercury is $0.45 \ Nm^{-1}$. The gain in surface energy is $...... \times 10^{-5} \ J$.

The amount of energy required to form a soap bubble of radius $2\,cm$ from a soap solution is nearly $..........\,\times 10^{-4}\,J$: (surface tension of soap solution $=0.03\,N\,m^{-1}$)

Explain surface energy and surface tension.

$A$ water drop breaks into $64$ identical droplets, each with a surface area of $10^{-7} \,m^2$. If the surface tension of water is $0.07 \,N/m$, what is the increase in surface energy during this process?

Twenty-seven droplets of water, each of radius $0.1 \,mm$, merge to form a single drop. Calculate the energy released during this process. (Take surface tension of water $T = 0.072 \,N/m$)