The heat evolved for the rise of water when one end of the capillary tube of radius r is immersed vertically into water is (Assume surface tension =T and density of water to be p)

Step-by-step solution

Water rise to height, h= 2 T g r Potential energy of water column, U= m g h 2 = 2 T^2 g The work performed by force of surface tension is W=2 r T h= 4 T^2 g From conservation of energy the heat evolved, Q=W-U= 2 T^2 g