Two narrow bores of diameters 3-0 mm and 6.0 mm are joined together to form a U-tube open at both the ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? (Surface tension of water at the temperature of the experiment is 72 dyne/cm. Take angle of contact to be zero and density of water to be 1.0 g/cc.)
We know water rises in the capillary tube.
Height to which water rises in the capillary tube is,
Therefore the height h1
of the water that rises in the limb of diameter 3 mm is given by,
The height h2
of the water that will rise in the limb of diameter 6 mm is given by,
Hence difference in the levels of two limbs is,