One end of a capillary tube is dipped in water, the rise of water column is ' h '. The upward force of 98 dyne due to surface tension is balanced by the force due to the weight of the water column. The inner circumference of the capillary is (surface tension of water =7 10⁻² Nm ⁻¹ )

Step-by-step solution

The upward force due to surface tension is F_T = T L , where T is the surface tension and L is the inner circumference of the capillary tube. Given that F_T = 98 dyne and the surface tension of water is 7 10⁻² N ,m ⁻¹ , convert T to CGS units to maintain consistency with the force unit. Since 1 , N = 10^5 dyne and 1 , m = 100 , cm : T = 7 10⁻² N m = 7 10⁻² 10^5 , dyne 100 , cm = 70 , dyne cm . Substituting into F_T = T L gives: 98 = 70 L . Solving for L yields L = 98 / 70 = 1.4 , cm , the inner circumference. There