A vertical capillary tube is brought in contact with the water surface (coefficient of surface tension T). The radius of the capillary is r and the angle of contact 0∘ is . If ρ is the density of water, the increase in the potential energy of the water due to capillary rise is
2πT2ρg
h=2Tr&g
Force due to surface tension, F=(2πr)(T)
Increase in potential Energy of water coloumn is equal to work done in displacing its centre of mass