Question

Water, (assumed to ‘spread out’ on glass), rises to a height h (above the general outside level) in a (very small radius) glass capillary tube. The surface tension of water may be taken as 70 N/m. If the same capillary tube were to be dipped in mercury (surface tension = 560 N / m, relative density = 13.35, angle of contact with glass = (π/2 + α) (α is an acute angle), the level of mercury, in the capillary tube, relative to the general outside level, would be

(1) at a height h’ where h’ = -1.67 cos α

(2) at a depth d₁ where d₁ = 0.6 cos α

(3) at a depth d₂ where d₂ = 0.6 sin α

(4) at a height h” where h” = -1.67 sin α

Answer 1

(3) at a depth d₂ where d₂ = 0.6 sin α