Two parallel glass plates are dipped partly in the liquid of density d keeping them vertical. If the distance between the plates is x surface tension for the liquid is T and angle of contact `theta`, then rise of liquid between the plates due to capillary will be

Options

A. `(T cos theta)/( xd)`
B. `(2T cos theta )/(xeg)`
C. `(2T)/(xdg cos theta)`
D. `(T cos theta)/(xdg)`

Answer

B

Explanation

Let the width of each plate is b and due to surface tension liquid will rise upto height h then upward force due to surface tension
`= 2 T b cos theta " "…(i)`
Weight of the liquid rises
in between the plates
`= V dg = (bxh) dg " "...(ii)`

Equation (i) and (ii) we get, `2T cos theta = xhdg`
`therefore h = (2T cos theta)/(xdg)`