Consider the following statements: If there were no phenomenon of capillarity 1. It would be difficult to use a kerosene lamp. 2. One would not be able to use a straw to consume a soft drink. 3. The blotting paper would fail to function. 4. The big trees that we see around would not have grown on the Earth. Which of the statements given above are correct?

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YESPYQ · Accepted Answer

Correct answer: 1, 3 and 4 only. Capillarity (or capillary action) is the ability of a liquid to flow in narrow spaces, such as thin tubes or porous materials, without the assistance of external forces and even against gravity. It occurs due to the cohesion (attraction between liquid molecules) and adhesion (attraction between the liquid and solid surface), along with surface tension. Statement 1 is correct: The oil in the wick of a lamp rises due to the capillary action of threads in the wick. Absence of capillarity would certainly make it difficult to use Kerosene lamps. Statement 2 is incorrect: There is no capillary action in using a straw to consume the soft drink as the consumer applies additional pressure from the mouth to consume the soft drink. Statement 3 is correct: A blotting paper soaks ink by the capillary action of the pores in the blotting paper. The blotting paper will not be useful without the capillarity phenomenon. Statement 4 is correct: The root-hairs of plants draw water from the soil through capillary action. Therefore absence of capillarity phenomenon would a

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