The shape of a liquid drop becomes spherical due to

The work done in increasing the size of a soap film from $10 \, cm \times 6 \, cm$ to $10 \, cm \times 11 \, cm$ is $3 \times 10^{-4} \, J$. The surface tension of the film is:

The force required to take away a flat circular plate of radius $2 \, cm$ from the surface of water will be (the surface tension of water is $70 \, dyne/cm$).

The property of surface tension is obtained in

At critical temperature,the surface tension of a liquid is

Two glass plates of area $10^{-2} \,m^2$ have a $10 \,cm$ thick water film between them. The surface tension of water is $70 \times 10^{-3} \,N/m$. The force required to separate the two glass plates from each other is (in $\,N$)