Question

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

• A. on the surface of the 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.

Height of water rise in capillary tube is $h=\frac{2T\cos \theta }{\rho d{g}_{eff}}$

When lift is accelerated downwards, the effective acceleration due to gravity is $g_{eff}=|g-a|$
Hence, the height through which the liquid rises in capillary tube must increase.