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 = I and density of water to be p)

We know that the water rises to a height tr given by h=2Tρgr Poteutial enerry of water columa U=mgh2=2πT2ρg The work done by the forca of surface tetraion W=2πrTh=4πT2ρg Applying the law of conservation of energy, the heat evolved Q=W−U=4πT2ρg−2πT2ρg=2πT2ρg