A perfectly wetting liquid has a theoretical capillary rise h₀ in a long tube, but the actual capillary tube extends only through a height L smaller than h₀ above the reservoir surface. Which statements are physically reasonable?
Select all that apply

Question

A perfectly wetting liquid has a theoretical capillary rise h₀ in a long tube, but the actual capillary tube extends only through a height L smaller than h₀ above the reservoir surface. Which statements are physically reasonable?

Select all that apply

G1 Physics · Accepted Answer

The usual formula h₀ = [2S cosθ]/[ρgr] assumes that the capillary tube is long enough to contain the equilibrium meniscus. If the physical tube ends below this predicted height, the liquid can reach the top, but the simple long-tube geometry no longer applies beyond the end. The meniscus and contact line must readjust near the rim, and overflow or spreading depends on the actual edge and wetting geometry. Therefore all four statements are physically reasonable.