Question

A liquid rises to a height of 1.8 cm in a glass capillary A. Another glass capillary B having diameter 90% of capillary A is immersed in the same liquid. The rise of liquid in capillary B is:

• A. 1.4 cm
• B. 1.8 cm
• C. 2.0 cm
• D. 2.2 cm

Answer 1

The correct option is C 2.0 cm

Using the equation for capillary action, $2Scos\theta =\rho grh$

$\Rightarrow$$rh=constant$

$\Rightarrow$$r_2{h}_2=r_1{h}_1$

Given : For $r_1=r$, Height upto which the liquid rises, $h_1=1.8$ cm

For $r_2=0.9r$, Let height upto which the liquid rises be, $h_2$

$\Rightarrow 0.9r\times h_2=r\times 1.8$

$\Rightarrow h_2=2.0cm$