Angle ?Capillary Tube - Jurin's Law A capillary tube (from the Latin capillus: hair) is a tube with a small internal diameter.The same junction angle is found at the free surface of a liquid near the edges of the container and causes the formation of a meniscus in tubes.of Liquid/Solid Junction A droplet of liquid placed on a flat, horizontal solid surface can: o Either spread widely (for example, water on clean glass); in this case, the liquid perfectly wets the solid, and the junction angle ?is 0?.

Angle θ of Liquid/Solid Junction
A droplet of liquid placed on a flat, horizontal solid surface can:
• Either spread widely (for example, water on clean glass); in this case, the liquid
perfectly wets the solid, and the junction angle θ is 0°.
• Or form a lens:
o If θ90°, the liquid does not wet the solid (for example, mercury on glass).
The same junction angle is found at the free surface of a liquid near the edges of the container
and causes the formation of a meniscus in tubes.
Capillary Tube - Jurin's Law
A capillary tube (from the Latin capillus: hair) is a tube with a small internal diameter. When
a capillary tube, open at both ends, is immersed in a liquid, the liquid "rises" (if θ90°) in the tube to a height h such that:
r g
2
h

 

cos
γ :is the surface tension,
θ : is the contact angle,
ρ : is the density of the liquid,
g : is the acceleration due to gravity,
r :is the radius of the