PROBLEM 4: A u-tube is made with two capillaries of diameters 0.8mm and 1.6mm respectively. The tube is held vertically and partially filled with liquid of surface tension is 0.065N/m and zero contact angle. Calculate the density of the liquid,if the difference between the level of two menisci is 15mm.

 

SOLUTION 4: Given that the diameters of capillaries are d₁ =0.8mm d₂ =1.6mm

Difference of level is h₁-h₂ =15mm

Angle of contact θ=0⁰

The equation of Capillary rise in the tube is

Substitute the given data to the above equation

We get