Question

If a capillary is dipped partially in water contained in a beaker which is placed inside a lift falling freely then the water:

• A. will rise upto the upper end of the capillary
• B. will rise upto a certain height only
• C. will not rise at all
• D. will oscillate in the capillary

Answer 1

The correct option is A will rise upto the upper end of the capillary

Height of liquid in capillary is $h=\frac{2Tcos\theta }{r\rho g}$

If the mass of the risen water is m and the lift is freely falling, then the lift is a non-inertial frame of reference where a pseudo force will act in a direction opposite of the acceleration of the frame.

the lift is accelerating with $g$ so the pseudo acceleration is $g$ upwards. So resultant value of g is zero.

So theoretically the rise is infinite.

Practically, no matter how tall the tube is, water will come out of it from the upper end as a fountain.