Capillary action is the ability of a liquid to flow in narrow spaces without external forces like gravity. It is sometimes called capillarity or wicking. There are two types of capillarity - capillarity rise, where liquids rise in small diameter tubes against gravity, and capillarity fall, where liquids are depressed in small diameter tubes against gravity. Capillary action is observed in many natural phenomena like the movement of water in plants and the drainage of tears from the eye.
2. Ability of a liquid to flow in narrow spaces without the
assistance of, and in opposition to, external forces like gravity
Capillary action is sometimes called capillarity, capillary
motion, or wicking
3. Drawing up of liquids between the hairs of a paint-brush
Drainage of constantly produced tear fluid from the eye
Observed in thin layer chromatography
draws ink to the tips of fountain pen nibs
moving groundwater from wet areas of the soil to dry areas
5. Tendency of liquids to rise in tubes of small diameter in
opposition to, external forces like gravity
6. Tendency of liquids to be depressed in tubes of small
diameter in opposition to, external forces like gravity
7. Lubricating oil spread easily on all parts because of their low
surface tension.
Cotton dresses are preferred in summer because cotton dresses
have fine pores which act as capillaries for sweat.
Dirt get removed when detergents are added while washing
clothes because surface tension of water is reduced.
8. The absorption of ink by a blotting paper is due to
capillary action, as the blotting paper is porous. When
it is placed over the ink, the ink raises into the pores.
Also rise of oil in the wick of a lamp is due to capillary
action.
If one end of a towel is dipped into a bucket of water
and the other end hangs over the bucket, the entire
towel soon becomes wet due to capillary action.
Supply of water to the leaves at the top of even a tall
tree is through capillary rise.
9. A fabric can be waterproof, by adding suitable
waterproofing materials to the fabric. This addition
increases the angle of contact, thereby making the
fabric waterproof.