Q. Water rises in a capillary tube to a height $h$. Choose false statement regarding capillary rise from the following.
A) On the surface of Jupiter, height will be less than $h$
B) In a lift moving up with constant acceleration height is less than $h$
C) On the surface of moon the height is more than $h$
D) In a lift moving down with constant acceleration height is less than $h$
Explanation
(d) The height $(h)$ to which water rises in a capillary tube is given by
$h = \frac{2T\ cos\theta}{r\rho g}$
where $\theta$ is angle of contact , $r$ the radius, $\rho$ the density and $g$ acceleration due to gravity.
When lift moves down with constant acceleration, height is less than $h$, because effective value of acceleration due to gravity increases hence $h$ decreases.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.