If the surface tension of water is $0.06 \, N/m$,then the capillary rise in a tube of diameter $1 \, mm$ is ....... $cm$ (assume $\theta = 0^\circ$,$g = 10 \, m/s^2$,and density of water $\rho = 1000 \, kg/m^3$).

Two capillaries of the same material but of different radii are dipped in a liquid. In one of the capillaries,the liquid rises to a height of $22 \ cm$ and in the other to $66 \ cm$. The ratio of their radii is

Why is moisture retained in the soil when a farm is ploughed?

Kerosene oil rises up the wick in a lantern due to:

Mercury has an angle of contact equal to $140^{\circ}$ with soda lime glass. $A$ narrow tube of radius $1.00 \; mm$ made of this glass is dipped in a trough containing mercury. By what amount does the mercury dip down (in $mm$) in the tube relative to the liquid surface outside? Surface tension of mercury at the temperature of the experiment is $0.465 \; N m^{-1}$. Density of mercury $= 13.6 \times 10^{3} \; kg m^{-3}$.

$A$ capillary tube of radius $0.1 \ mm$ is partly dipped in water (surface tension $70 \ dyn/cm$ and glass-water contact angle $\simeq 0^{\circ}$) inclined at $30^{\circ}$ with the vertical. The length of water risen in the capillary is . . . . . . $cm$. (Take $g = 980 \ cm/s^2$)