Fill in the Blank :

$(i)$ Bubble in water have .......... free surface.

$(ii)$ Bubble in air have .......... free surface.

$(iii)$ Rain drop have .......... free surface.

Pressure inside two soap bubbles are $1.01$ and $1.02$ atmosphere, respectively. The ratio of their volumes is

Excess pressure of one soap bubble is four times more than the other. Then the ratio of volume of first bubble to another one is

A drop of water of volume $0.05\, cm^3$ is pressed between two glass plates, as a consequence of which it spreads and occupies an area of $40\, cm^2$. If the surface tension of water is $70\, dyne/cm$, then the normal force required to separate out the two glass plates will be in Newton

There is a small hole in hollow sphere. Water enters in sphere when it is taken at depth of $40\,cm$ in water. Diameter of hole is ....... $mm$ (Surface tension of water $= 0.07\, N/m$):

A capillary tube of radius $r$ is dipped in a liquid of density $\rho$ and surface tension $S$. If the angle of contact is $\theta$, the pressure difference between the two surfaces in the beaker and the capillary