What substance present in our body balances the atmospheric pressure acting on us?

What conclusion do you get from the observation that a fountain of water is created at the leaking joint of pipes of the main water supply line?

What type of pressure is involved in the filling of a liquid in a syringe?

Where will the atmospheric pressure be greater-at ground level or at the top of high mountain ?

Name any two devices used in everyday life which work on the existence of atmospheric pressure.