Two parallel glass plates are dipped partly in the liqu

Two parallel glass plates are dipped partly in the liqu
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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.

Tcos θxd

B.

2Tcos θxdg

C.

2Txdgcos θ

D.

Tcos θxdg

Please scroll down to see the correct answer and solution guide.

Right Answer is: B

SOLUTION

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 θ

Weight of the liquid rises in between the plates = Vdg=(bxh)dg

Equating (i) and (ii) we get, 2Tcos θ=bxhdg

h=2Tcos θxdg