Question

The absorption of ink by blotting paper involves:
1. Viscosity of ink
2. Capillary action phenomenon
3. Diffusion of ink through the blotting
4. Siphon action

Answer 1

Correct Answer - Option 2 : Capillary action phenomenon

The correct answer is Capillary action phenomenon.

• The absorption of ink by the blotting paper is based on the capillary action phenomenon because the blotting paper is a thin and smooth paper that allows a little thicker liquid like ink to absorb on its surface.
• In this process of absorption, the cohesive force of ink is greater than the adhesive force of bloating paper and hence capillary action takes place.
• Capillary action is the liquid ability to flow in narrow spaces without the assistance of, or even in opposition to, external forces.
• Tubes having very small diameters (narrow cylindrical tubes) are known as capillaries.
• If these narrow tubes dipped in a liquid then the liquid in the capillary either rises falls relative to the surrounding liquid level. This phenomenon is known as capillary action.
• This occurs due to cohesive and adhesive forces.

​

• The water amount that is held in the capillary also determines the force with which it will rise.
• The material that surrounds the holes fills the pores also forms a film over them.
• This can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube.