 When a capillary tube is dipped in a liquid, the liquid rises to a height h in the tube. The free liquid surface inside the tube is hemispherical in shape. The tube is now pushed down so that the height of the tube outside the liquid is less than h. Then(A) The liquid will come out of the tube like in a small fountain.(B) The liquid will ooze out of the tube slowly.(C) The liquid will fill the tube but not come out of its upper end.(D) The free liquid surface inside the tube will not be hemispherical. Verified
119.4k+ views
Hint : It is given that a capillary tube is dipped into the water tub, the water rises to a height h in the tube. Now it is said that the tube is further pushed inside the tub, so that the undipped part height is lesser than h. Now, it is essential to understand that due to capillarity and surface tension , the liquid will be held and rather won’t come out of the tube. Using this , find the appropriate choice.

$\Rightarrow h = \dfrac{{2T}}{{r\rho g}}$
Where T is the surface tension of the fluid , r is assumed to be the radius of the meniscus formed on the tube and $\rho$ to be the density of the fluid.