Correct Option
(B) Capillarity describes the phenomenon where a liquid moves in narrow spaces due to surface tension and adhesive/cohesive forces. The general rising of underground water is primarily driven by hydrostatic pressure, the permeability of geological strata, and gravitational forces. While capillary action can occur in very fine soil pores, it is not the principal mechanism responsible for the overall rise of underground water levels.
Incorrect Options
- (1) Blotting of ink: Blotting paper is a porous material with fine capillaries. Ink is absorbed into these capillaries through capillary action, where adhesive forces between ink and paper exceed cohesive forces within the ink.
- (3) Spread a water drop on a cotton cloth: Cotton cloth is composed of numerous fine fibers, creating capillary spaces. Water spreads across the cloth due to capillary action as it adheres to the cotton fibers and moves into these spaces.
- (4) Rising of water from the roots of a plant to its foliage: Water transport in plants, specifically through the xylem vessels, is significantly influenced by capillary action. Xylem forms a network of narrow tubes, facilitating the upward movement of water due to capillary forces, further aided by transpiration pull.