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 $g = 10 \ ms^{-2}$):

When an airplane flies at a higher altitude,it is not advisable to keep a fountain pen in one's pocket. Why?

$A$ 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 height to which a cylindrical vessel must be filled with a homogeneous liquid,such that the average force with which the liquid presses the side of the vessel is equal to the force exerted by the liquid on the bottom of the vessel,is equal to:

The atmospheric pressure and height of the barometer column are $10^5 \, Pa$ and $760 \, mm$ respectively on the Earth's surface. If the barometer is taken to the Moon,then the column height will be ........ $mm$.

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