Question

A capillary of length L is put into water and liquid rises upto h (L>h). Now length of capillary is reduced to h/2 and put into water again, then the liquid will:

(a) Come out like a fountain

(b) Not come out at all

(c) Come out initially then stop

(d) Not rise in the capillary

Solution

Surface tension prevents water from overflowing. Water will never come out of capillary tube.

As height decreses, radius of curvature increases by using Jurin's law.

Jurin's law

HR = constant, where R is radius of curavture and H is the liquid height.

Therfore, option (b) is correct.