When a capillary is dipped in water,water rises $0.015 \ m$ in it. If the surface tension of water is $75 \times 10^{-3} \ N/m$,the radius of the capillary is ....... $mm$.

$A$ $20 \ cm$ long capillary tube is dipped in water. The water rises up to $8 \ cm$. If the entire arrangement is put in a freely falling elevator,the length of the water column in the capillary will be ....... $cm$.

The ratio of surface tensions of mercury and water is given to be $7.5$ while the ratio of their densities is $13.6$. Their contact angles with glass are close to $135^o$ and $0^o$,respectively. It is observed that mercury gets depressed by an amount $h$ in a capillary tube of radius $r_1$,while water rises by the same amount $h$ in a capillary tube of radius $r_2$. The ratio $(r_1/r_2)$ is then close to:

$A$ 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 $g = 980 \ cm/s^2$)

When one end of a capillary tube is dipped in water,the height of water column is $h$. The upward force of $105 \text{ dyne}$ due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary tube is (Surface tension of water $= 7 \times 10^{-2} \text{ N/m}$) (in $\text{ cm}$)

The radius of a capillary tube is $2 \times 10^{-3} \ m$. If a liquid of weight $6.28 \times 10^{-4} \ N$ can be supported in the capillary,what is the surface tension of the liquid?