In a capillary,the pressure below the curved surface of water will be:

Give reason: The lighting of a lamp is due to the wick of the lamp.

$A$ glass capillary tube of internal radius $r = 0.25 \, mm$ is immersed in water. The top end of the tube projects $2 \, cm$ above the surface of the water. At what angle does the liquid meet the tube (in $^{\circ}$)? (Surface tension of water $T = 0.07 \, N/m$,density $\rho = 1000 \, kg/m^3$,$g = 9.8 \, m/s^2$)

$A$ capillary tube of radius $0.2\,cm$ is dipped vertically in a beaker containing liquid. If the liquid rises to a height of $5\,cm$ for which the angle of contact is $60^o$,then the surface tension of the liquid is ...... $dynes/cm$ (given density $d = 1\,gm/cm^3$ and acceleration due to gravity $g = 980\,cm/s^2$).

The sap in a tree rises in a system of capillaries of radius $2.5 \times 10^{-5} \, m$. The surface tension of the sap is $7.28 \times 10^{-2} \, N \, m^{-1}$ and the angle of contact is $0^{\circ}$. The maximum height to which the sap can rise in a tree through capillarity action is ...... $m$ (take $\rho_{sap} = 10^3 \, kg \, m^{-3}$ and $g = 9.8 \, m \, s^{-2}$).

In a capillary tube experiment,a vertical $20 \,cm$ long capillary tube is dipped in water. The water rises up to a height of $8 \,cm$ due to capillary action. If this experiment is conducted in a freely falling elevator,the length of the water column becomes ....... $cm$.