Water rises to a height of $10 \ cm$ in a certain capillary tube. Another identical tube when dipped in mercury,the level of mercury is depressed by $3.42 \ cm$. The density of mercury is $13.6 \ g/cc$. The angle of contact for water in contact with glass is $0^o$ and for mercury in contact with glass is $135^o$. The ratio of the surface tension of water to that of $Hg$ is:

Two capillary tubes $P$ and $Q$ are dipped in water. The height of the water level in capillary $P$ is $2/3$ of the height in capillary $Q$. The ratio of their diameters is:

The following observations were taken for determining surface tension $T$ of water by the capillary method:
Diameter of capillary,$D = 1.25 \times 10^{-2} \; m$
Rise of water,$h = 1.45 \times 10^{-2} \; m$
Using $g = 9.80 \; m/s^2$ and the simplified relation $T = \frac{rhg}{2} \times 10^3 \; N/m$,the possible error in surface tension is ........... $\%$. (Assume the least count of the measuring instrument is $0.01 \times 10^{-2} \; m$)

$A$ capillary tube made of glass is dipped into mercury. Then

$A$ vertical glass capillary tube of radius $r$ open at both ends contains some water (surface tension $T$ and density $\rho$). If $L$ be the length of the water column,then:

Water rises up to a height of $4 \,cm$ in a capillary tube. The lower end of the capillary tube is at a depth of $8 \,cm$ below the water level. The mouth pressure required to blow an air bubble at the lower end of the capillary will be '$X$' $cm$ of water,where $X$ is equal to