It is not possible to write directly on blotting paper or newspaper with an ink pen.

The surface tension for pure water in a capillary tube experiment is

$A$ glass rod of radius $1.0\,mm$ is inserted symmetrically into a vertical capillary tube of radius $2.0\,mm$ such that their lower ends are at the same level. This arrangement is now dipped in water. The height to which water will rise into the tube will be ...... $mm$ (Surface Tension of water $T = 75 \times 10^{-3}\,N/m$,density $\rho = 10^3\,kg/m^3$,$g = 10\,m/s^2$).

$A$ capillary tube of radius $R$ is dipped in water,and water rises to a height $H$. The mass of water in the capillary tube is $M$. If a capillary tube of half the radius is dipped in water,what will be the mass of the water in the capillary tube?

Water rises to a height of $15 \,mm$ in a capillary tube having cross-sectional area $A$. If the cross-sectional area of the tube is made $A / 3$, then the water will rise to a height of:

Two capillary tubes $A$ and $B$ of the same internal diameter are kept vertically in two different liquids whose densities are in the ratio $4:3$. If the surface tensions of these two liquids are in the ratio $6:5$,then the ratio of rise of liquid in capillary $A$ to that in $B$ is (assume their angles of contact are nearly equal).