Upon dipping a capillary tube into a liquid, the liquid level neither rises nor falls within the capillary.

Step-by-step solution

The height of the liquid column in a capillary tube is given by Jurin's law: h = 2T g r where T is the surface tension, is the angle of contact, is the density of the liquid, g is the acceleration due to gravity, and r is the radius of the capillary tube. Given that the liquid level neither rises nor falls, h = 0 . 2T g r = 0 Since , g , and r are non-zero constants for a given setup, we must have: T = 0 This implies that either T = 0 or = 0 . If = 0 , then the angle of contact = 90^ . If T = 0 , then the surface t