Variation of atmospheric pressure with height from the Earth is ................

Mention two instruments which measure the atmospheric pressure.

$A$ submarine has a window of area $30 \times 30 \,cm^2$ on its ceiling and is at a depth of $100 \,m$ below sea level. If the pressure inside the submarine is maintained at the sea-level atmospheric pressure,then the force acting on the window is ............. $N$ (consider density of sea water $\rho = 1.03 \times 10^3 \,kg/m^3$,acceleration due to gravity $g = 10 \,m/s^2$).

The figure shows a siphon. Choose the wrong statement: ($P_0 =$ atmospheric pressure)

Why does an air bubble formed in water grow in size as it rises from the bottom to the surface? Explain.

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: