Two parallel glass plates are dipped partly in the liquid of denstiy 'd' keeping them vertical. If the distance between the plates is 'x', Surface tension is T and angle of contact is `theta` then ries of liquid between the plates due to capillary will be

Options

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

Answer

B

Explanation

Let `L` be the width of plates (perpendicular to paper inwards).
Surface tension force in upward direction
= weight of liquid of height h
`:. Tl cos theta=Vdg (V=` volume)

or `T(2L)cos theta=(Lxh)dg` .
`:. h = (2T cos theta)/(xdg)`