The gauge pressure at a depth of $50 \,m$ in a sea is (Density of sea water is $1025 \,kg \,m^{-3}$ and $g=10 \,ms^{-2}$ ). (in $\,Pa$)

$A$ 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 ........ $cm$.

$A$ tank of oil has a height of $4 \,m$ and a density of $850 \,kg \,m^{-3}$. The gauge pressure at the bottom of the tank is (Given: $1 \,atm = 10^5 \,Pa$,Acceleration due to gravity $g = 10 \,m \,s^{-2}$) (in $\,kPa$)

Explain why water storage dam walls are thicker at the bottom.

The height of a mercury barometer is $75 \ cm$ at sea level and $50 \ cm$ at the top of a hill. The ratio of the density of mercury to that of air is $10^4$. The height of the hill is ....... $km$.

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