• question_answer 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 $=7.5\times {{10}^{-2}}N{{m}^{-1}}$ and $g=10\,m{{s}^{-2}}$) A)  $0.3$ cm                                 B)  3 mm C)  3 cm                            D)  3m

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