A U-rube is made up of two capillaries of diameters 1.5 mm and 2.0 mm, respectively. The U-tube is kept vertically and partially filled with water of surface tension 0.07 N/m and zero contact angle....

A U-rube is made up of two capillaries of diameters 1.5 mm and 2.0 mm, respectively. The U-tube is kept vertically and partially filled with water of surface tension 0.07 N/m and zero contact angle. Calculate the difference in the level caused by the capillarity.

Calculate the capillary effect in mm in a glass tube of 6 mm diameter when immersed in (i) water, and (ii) mercury, both liquids being at 20°C. Assume a to be 73 X
 Nim for water and 0.5 N/m for mercury. The contact angles for water and mercury are zero and 130°, respectively.