A capillary tube of radius r is immersed in water and water rises in to a height h. The mass of water in the capillary tube is 5g. Another capillary tube of radius 2 r is immersed in water. The mass of water that will rise in this tube is

Options

A. 2.5g
B. 5.0g
C. 10g
D. 20 g

Answer

C

Explanation

Let h be the height through which the liquid rises in the capillary tube of radius r.
`:. h= (2S cos theta)/(r rho g)`
Mass of the water in the first tube is `m= pi r^(2) h rho = pi r^(2) ((2S cos theta)/(r rho g)) rho = (pi r 2S cos theta)/(g)`
or `m prop r :. (m.)/(m) = (r.)/(r ) = (2r)/(r ) = 2`
or `m. = 2m = 2xx 5g = 10g`