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The pressure in a liquid is not the same at all depths. The pressure exerted by a liquid changes with depth in the liquid.The pressure exerted by a liquid is small just under the surface of the liquid. But as we go  deeper in a liquid, the pressure of liquid increases. We will now describe an activity to show that the pressure of a liquid depends on its depth.

Take a tall vessel having three short and thin tubes A,B and C fitted at different depths from the top of the vessel. The three tubes are of equal diameters and corks are fitted into them. The vessel is filled with water and then all the corks are removed quickly. On removing the corks, the water from the uppermost tube A is found to travel the shortest distance from the base of the vessel, the water from  middle tube B goes a little farther away where as the water from the lowermost tube C shoots out farthest of all. This can be explained as follows:

The depth of water near tube A is small so the water comes out from tube A with smaller pressure and falls nearer the bottom of the vessel. The depth of water near tube B is greater, so the water comes out with greater pressure from tube B and falls farther away from the base of the vessel. The depth of water near tube C with the greatest pressure and goes farther from the vessel. This means that as the depth of water increases from A to B to C, the pressure of water gradually increases.

From the above activity we conclude that as the depth of water in the vessel increases,the pressure exerted by water also increases.In general,we can say that the pressure of a liquid increases with depth.