Question

Water rises in a capillary tube to a height $h$. It will rise to a height more than $h$ :

• A. on the surface of sun
• B. in a lift moving down with an acceleration
• C. at the poles
• D. in a lift moving up with an acceleration.

Answer 1

The correct option is B in a lift moving down with an acceleration

Capillary rise in a tube when it is immersed in a liquid is:
$h=\frac{2T\cos \theta }{\rho rg}$ where
h- height the liquid rises
r is the radius of the tube,
T is the surface tension of the liquid,
$\theta$ is the contact angle
g is the acceleration due to gravity
In a lift moving downward with acceleration a, effective g is (g-a)
Since g is in the denominator in the expression for height h, height h will increase.