$A$ beaker containing a liquid of density $\rho$ moves up with an acceleration $a$. The pressure due to the liquid at a depth $h$ below the free surface of the liquid is

$A$ $U$-shaped tube is partially filled with an incompressible liquid of density $1.2 \ g \ cm^{-3}$. Oil, which does not mix with the liquid, is poured into the left side of the $U$-tube until the liquid rises by $15 \ cm$ on the right side. If the density of the oil is $0.9 \ g \ cm^{-3}$, the oil level will stand higher than the liquid level on the right side of the $U$-tube by: (in $cm$)

From the adjacent figure,the correct observation is:

$A$ swimming pool has a depth of $3 \,m$. The pressure at the bottom of the pool due to water alone is: (Density of water is $1000 \,kg \,m^{-3}$, Acceleration due to gravity $= 10 \,m \,s^{-2}$)

Water stands up to height $h$ behind a dam as shown in the figure. The front view of the dam gate is also shown in the adjoining figure. The density of water is $\rho$ and the acceleration due to gravity is $g$. If the atmospheric pressure force is also considered,the point of application of the total force acting on the dam due to water above $O$ is:

The diagram shows a simple mercury barometer. Which of the following does not cause the height of the mercury column to vary?