Question

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

Options

• a lift going upward with a certain acceleration

• accelerating train

• a satellite rotating close to earth

• a lift going down with acceleration a < g

Answer 1

A lift going down with acceleration a < g

Explanation:

The height of liquid column in a capillary tube is

h = `(2"T" cos theta)/(rho "rg") => "h" prop 1/"g"`

∴ When the setup is kept in a lift going down with acceleration a < g, then the height of water in the tube increases as net downward acceleration becomes (g - a).