Capillary Action Concept

Demonstrations in Capillary Action

Top: projected image of capillary tubes showing water at different heights. Bottom: the apparatus -- five glass capillary tubes of increasing diameter mounted on a clear base with a wide reservoir tube on the right.

Capillary Tubes

Water rises to different heights in a set of glass tubes with increasing diameters, directly showing the inverse relationship between capillary rise and tube radius.
Two U-shaped glass tubes against a dark background, each with one wide arm and one narrow arm connected at the bottom
Safety

Capillary Action 1

Two U-tubes (each with one wide and one narrow arm) show capillary rise with water and capillary depression with mercury, contrasting wetting and non-wetting behavior. **Note: This demo is currently …
Capillary siphon apparatus: clear box with U-shaped capillary tubes mounted on a rod and stand, shown both directly and projected via horizontal projector
Safety

Capillary Action 2

Capillary action in narrow tubes draws water over a barrier, initiating siphon flow without external priming. Students observe how surface tension forces at the molecular scale can start macroscopic fluid …
Glass wedge apparatus on a lab jack: two glass plates forming a narrow wedge, with a visible capillary curve where water rises higher at the narrow end

Capillary Curve

A wedge-shaped glass container produces a continuous capillary curve, showing the inverse relationship between gap width and capillary rise. Students see the entire relationship simultaneously in a single apparatus.