The figure shows two containers $P$ and $Q$ with the same base area $A$,each filled to the same height with the same liquid. Select the correct alternative.

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

$A$ barometer is constructed using a liquid (density $= 760 \; kg/m^3$). What would be the height (in $m$) of the liquid column,when a mercury barometer reads $76 \; cm$? (density of mercury $= 13600 \; kg/m^3$)

The pressure at a point $10 \ m$ below the surface of water is (take atmospheric pressure $P_0 = 1.01 \times 10^5 \ Nm^{-2}$ and $g = 10 \ ms^{-2}$):

$A$ barometer kept in an elevator reads $76 \, cm$ when it is at rest. If the elevator goes up with some acceleration, the reading will be .......... $cm$.

The atmospheric pressure at a place is $10^5 \,Pa$. If tribromomethane (specific gravity $= 2.9$) is employed as the barometric liquid,the barometric height is .......... $m$. (in $.52$)