Fluid Mechanics

When one end of a capillary tube is dipped in water, the height of water column is ' $h$ '. The upward force of 105 dyne due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary tube is

(Surface tension of water $=7 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ )