Prelims 2012 · Science and Technology · Question 93
Consider the following statements: If there were no phenomenon of capillarity<br/>1. It would be difficult to use a kerosene lamp.<br/>2. One would not be able to use a straw to consume a soft drink.<br/>3. The blotting paper would fail to function.<br/>4. The big trees that we see around would not have grown on the Earth.<br/><br/>Which of the statements given above are correct?
Answer
1, 3 and 4 only
1. Kerosene lamp — Correct. The wick draws kerosene upward by capillary action; without capillarity, fuel would not reach the flame properly.
2. Drinking with a straw — Incorrect. A straw works mainly due to pressure difference created by sucking, not capillarity.
3. Blotting paper — Correct. Blotting paper absorbs ink/liquid through its fine pores by capillary action; without it, it would not work.
4. Growth of big trees — Correct. Upward movement of water in narrow xylem vessels is aided by capillarity (along with cohesion-transpiration mechanisms); without this effect, tall trees could not grow as they do.
Hence, statements 1, 3 and 4 are correct.