Question

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 liquids is T and angle of contact is θ , then rise of liquid between the plates due to capillary will be

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

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 = $2Tbcos\theta$

Weight of the liquid rises in between the plates = $Vdg=\left(bxh\right)dg$

Equating (i) and (ii) we get, $2Tcos\theta =bxhdg$

$\therefore h=\frac{2Tcos\theta }{xdg}$