Question

The rise in the level of a liquid in a tube is h. What will be the rise in the level if the same amount of liquid is poured into a tube of half the diameter.

(a) 0

(b) h/2

(c) h

(d) 2h

This question was addressed to me during an online exam.

My doubt stems from Surface Tension topic in division Properties of Fluids of Fluid Mechanics

Answer 1

Right answer is (d) 2h

To elaborate: where h = rise in liquid height in the tube, S = surface tension, θ = the angle of contact, d = diameter of the tube, ρ = density of liquid and g = acceleration due to gravity. All other factors remaining constant, h α d. Thus, if d is halved, h will be doubled.