Discussion Forum



1)

Water rises up to a height h in a capillary tube on the surface of the earth. The value of h will increases if the experimental setup is kept in [ g=acceleration due to gravity]


A) a lift going upward with a certain acceleration

B) accelerating train

C) a satellite rotating close to earth

D) a lift going down with acceleration a < g

Answer:

Option D

Explanation:

 The height  of liquid column in capillary tube is 

 $h=\frac{2T\cos\theta}{\rho rg}\Rightarrow h\propto\frac{1}{g}$

 $\therefore$   when the setup is kept ina lift going down with acceleration a < g, then the height of water in the tube increases as net downward acceleration becomes (g-a)