$A$ liquid is coming out from a vertical tube. The relation between the weight of the drop $W$,surface tension of the liquid $T$,and radius of the tube $r$ is given by,if the angle of contact is zero.

What causes the free surface of a liquid to have minimum area?

The force necessary to pull a circular plate of $5\, cm$ radius from a water surface,for which the surface tension is $75\, dynes/cm$,is

On what does the value of surface tension depend? Explain.

$A$ circular film of a liquid has an area of $10 \,cm^2$. If the work done in increasing its radius to two times the initial radius is $8 \times 10^{-3} \,J$, the surface tension of the liquid is $\left(1+\frac{1}{\alpha}\right) \,N/m$. The value of $\alpha$ is

When water is heated,bubbles form at the bottom and detach to rise. Let the radius of the bubble be $R$. The bubble is in circular contact with the bottom of the container with a radius $r$. If $r \ll R$ and the surface tension of water is $T$,find the value of $r$ just before the bubble detaches from the container. (Density of water is $\rho_w$)