Exercise 1

The surface tension of a liquid is $5 {\mathrm{Nm}}^{-1}$. If a film is held on a ring of area $0.02{ \mathrm{m}}^2$, its surface energy is about:

Surface tension of liquid is $5 {\mathrm{Nm}}^{-1}$. If a thin film of area $0.02{ \mathrm{m}}^2$ is made in a ring then the surface energy will be :

Soap helps in cleaning clothes, because

If $T$ is the surface tension of a fluid, then the energy needed to break a liquid drop of radius $R$ into $64$ equal drops is

The work done in blowing a soap bubble of $10 \mathrm{cm}$ radius is (surface tension of soap solution is $0.03 \mathrm{N} {\mathrm{m}}^{-1}$)

Which one of the following is not a result of surface tension?

The radii of two soap bubbles are $r_1$ and $r_2$. In isothermal conditions, two meet together in a vacuum. Then the radius of the resultant bubble is given by:

The excess pressure inside an air bubble of radius $r$ just below (inside) the surface of the water is ​$P_1$. The pressure inside a drop of the same size (radius) which is just outside the water surface is $P_2$. If $T$ is the surface tension then