On putting a capillary tube in a pot filled with water,the level of water rises up to a height of $4 \,cm$ in the tube. If a tube of half the diameter is used instead,the water will rise to a height of nearly ............. $cm$.

The lower end of a capillary tube is dipped into water and it is observed that the water in the capillary tube rises by $7.5 \ cm$. Find the radius of the capillary tube used,if the surface tension of water is $7.5 \times 10^{-2} \ N \ m^{-1}$. The angle of contact between water and glass is $0^{\circ}$ and the acceleration due to gravity is $10 \ m \ s^{-2}$.

$A$ $20\, cm$ 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 water column in the capillary tube will be ...... $cm$.

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

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?

The angle of contact between glass and water is $0^\circ$ and it rises in a capillary up to $6 \text{ cm}$ when its surface tension is $70 \text{ dynes/cm}$. Another liquid of surface tension $140 \text{ dynes/cm}$,angle of contact $60^\circ$ and relative density $2$ will rise in the same capillary by ........ $\text{cm}$.