How does a manometer work
Answers
If one side is connected to a gas supply, the gas exerts a pressure on one surface(A) and level (B) rises until
Pressure of gas= Atmospheric pressure+ Pressure exerted by liquid on a point.
Basically, it uses the property of liquids which states that they are incompressible and pass on any pressure applied to them so that the level of liquid on one side will increase to make pressure at any horizontal points in the liquid equal.
Aim: To understand the working of a manometer. From a rubber balloon, cut a small piece of rubber and cover the mouth of a thistle funnel using this cut portion. Connect the thistle funnel using a rubber tube with the manometer. Fill the manometer with a coloured liquid. The manometer consists of a glass tube in which the liquid is filled. The glass tube is supported by a wooden board and it has graduations marked on it. Dip the thistle funnel in a beaker filled with water. Mark this position as A. Note the reading in the manometer. Lower the funnel deeper into the beaker and mark this position as B. Note the reading again in the manometer. Now, note the difference in the two readings. This difference tells us the pressure exerted by the liquid at different depths.