$A$ drop of liquid of density $\rho$ is floating half-immersed in a liquid of density $d$. If $T$ is the surface tension,then the diameter of the drop is:

The shown $H$-shaped apparatus contains an ideal incompressible liquid and has dimensions as shown in the figure. The diameters of the tubes are small compared to $h$ and $R$. The apparatus is rotated with a constant angular velocity $\omega$ about a symmetric vertical axis as shown in the figure. The pressure at point $A$ is

Water coming out of a horizontal tube at a speed $v$ strikes a vertical wall normally,close to the mouth of the tube,and falls down vertically after impact. When the speed of water is increased to $2v$:

$A$ light semi-cylindrical gate of radius $R$ and length $l$ is pivoted at its midpoint $O$ of the diameter as shown in the figure,holding liquid of density $\rho$. The force $F$ required to prevent the rotation of the gate is equal to:

An incompressible liquid is kept in a container having a weightless piston with a hole. $A$ capillary tube of inner radius $0.1 \,mm$ is dipped vertically into the liquid through the airtight piston hole,as shown in the figure. The air in the container is isothermally compressed from its original volume $V_0$ to $\frac{100}{101} V_0$ with the movable piston. Considering air as an ideal gas,the height $(h)$ of the liquid column in the capillary above the liquid level in $cm$ is. . . . . . .
[Given: Surface tension of the liquid is $0.075 \,N \,m^{-1}$,atmospheric pressure is $10^5 \,N \,m^{-2}$,acceleration due to gravity $(g)$ is $10 \,m \,s^{-2}$,density of the liquid is $10^3 \,kg \,m^{-3}$ and contact angle of capillary surface with the liquid is zero]

When an air bubble rises from the bottom of a lake to the surface,its radius is doubled. The atmospheric pressure is equal to that of a column of water of height $H$. The depth of the lake is: