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 10⁻² ~N / m )

Step-by-step solution

The upward force due to surface tension in a capillary tube is given by F = T L where T represents surface tension, L the inner circumference, and the angle of contact. For water in a clean glass capillary, 0^ , simplifying to = 1 , so the relation becomes F = T L Given the upward force F = 105 dyne , surface tension of water T = 7 10⁻² N/m , and the conversion 1 N = 10^5 dyne , the force in SI units is F = 1.05 10⁻³ N Solving for circumference: L = F T = 1.05 10⁻³ 7 10⁻² = 0.015 m Converting to centimeters, L = 1.