If the liquid level falls in a capillary tube,then the radius of the capillary will:

$A$ narrow glass capillary tube of radius $1.00 \ mm$ is dipped in a trough containing mercury. The amount by which the level of mercury dips down relative to the normal level outside the tube will be approximately $..... \ mm$.
$[$Surface tension of mercury at room temperature $= 0.465 \ N/m$,density of mercury $= 13.6 \times 10^3 \ kg/m^3$,angle of contact with glass $= 135^{\circ}$,$g = 9.8 \ m/s^2]$

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 ............. $cm$.

$A$ uniform capillary tube of length $l$ and inner radius $r$ with its upper end sealed is submerged vertically into water. The outside pressure is $p_{0}$ and surface tension of water is $\gamma$. When a length $x$ of the capillary is submerged into water,it is found that water levels inside and outside the capillary coincide. The value of $x$ is

$A$ capillary tube stands with its lower end dipped into a liquid for which the angle of contact is $90^{\circ}$. The liquid will

$A$ capillary tube of radius $0.1 \,mm$ is dipped in water. The water rises to a height of $2 \,cm$ in the tube. If the surface tension of water is $0.072 \,N/m$, the contact angle between water and the wall of the tube is: