Q. A vessel whose bottom has round hole with diameter of 1 mm is filled with water. Assuming that surface tension acts only at hole, then the maximum height to which the water can be filled in vessel without leakage is(surface tension of water $= 7.5 \times 10^{- 2}\ {Nm}^{- 1\ }and\ g = 10{ms}^{- 2})$

A) 0.3 cm
B) 3 mm
C) 3 cm
D) 3 m
Explanation

(c) Water will not leak out from the hole if the weight of water in the water column is supported by the force due to surface tension.
Using the relation,
$h = \frac{2T}{r\rho g}$
$= \frac{2 \times 7.5 \times 10^{- 2}}{0.5 \times 10^{- 3} \times 10^{3} \times 10}$
$= 3 \times 10^{- 2}\ m = 3\ cm$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.