Q 11-09-009NEETNEET 2020Top questionMedium
A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is $5$ g. Another capillary tube of radius $2$r is immersed in water. The mass of water that will rise in this tube is :
Answer: (C) $10.0$ g
Concept. $h = \dfrac{2S\cos\theta}{r\rho g} \propto \dfrac1r$, so the raised mass $\pi r^2h\rho \propto r$.
Step 1. Double $r$. The mass doubles: $10$ g.
Answer. $10.0$ g (Option C).
Solution by Sreeraj P, M.Sc Physics