Question

Two capillary tubes A and B of radii 0.2 cm and 0.4 cm are dipped in the same liquid. The ratio of heights through which liquid rises in the tubes A and B is:

• A. $1:2$
• B. $2:1$
• C. $1:4$
• D. $4:1$

Answer 1

The correct option is B $2:1$

By using rise in capillary tube formula
$h=\frac{2Tcos\theta }{\rho gr}$
$h_A=\frac{2T\left(1\right)}{\rho \left(0.2\right)g}$ ---------(1)
$h_B=\frac{2T\left(1\right)}{\rho \left(0.4\right)g}$ ---------(2)
Dividing (1) and (2) we get
$\frac{h_A}{h_B}=\frac{0.4}{0.2}=2$
Hence, ratio of heights in A and B is $2:1$