Question

Two capillary tubes of same diameter are put vertically one each in two liquids whose relative densities are 0.8 and 0.6 and surface tensions are 60 and 50 dyne/cm respectively. Ratio of heights of liquids in the two tubes $\frac{h_1}{h_2}$ is

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

Ascent formula $h=\frac{2Tcos\theta }{rdg}$
$\Rightarrow \frac{h_1}{h_2}=\frac{T_1}{T_2}\times \frac{d_2}{d_1}$ (r, $\theta$ and g are constants)
$=\frac{60}{50}\times \frac{0.6}{0.8}=\frac{9}{10}$