$A$ sudden drop in the mercury level by $10 \,mm$ or more is a sign of ..........

$A$ 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 ............

$A$ 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

The pressure at half the depth of a lake is $2/3$ of the pressure at its bottom. What is the depth of the lake in $m$?

The pressure at the bottom of a water tank is $4 P$,where $P$ is atmospheric pressure. If water is drawn out until the water level decreases by $\frac{3}{5}$ of its initial height,then the pressure at the bottom of the tank is .........

$A$ barometer tube reads $76 \ cm$ of mercury. If the tube is gradually inclined at an angle of $60^\circ$ with the vertical,keeping the open end immersed in the mercury reservoir,the length of the mercury column will be ........ $cm$.