Question

A glass capillary tube has a radius of $0.05\text{cm}$. The tube is dipped in a container filled with water $($surface tension of water $=0.075{\text{Nm}}^{–1})$. What is the height of water rise in capillary tube due to capillary action?

• A. $4\text{cm}$
• B. $5\text{cm}$
• C. $3\text{cm}$
• D. $6\text{cm}$

Answer 1

The correct option is C $3\text{cm}$

Height of liquid column inside capillary tube,

$h=\frac{2S\cos \theta }{\rho gr}$

Here, for water-glass, $\theta =0^{\circ }$
$r=5\times {10}^{-4}\text{m},\rho ={10}^3{\text{kg/m}}^3$

So,

$h=\frac{2\times 0.075}{1000\times 10\times 5\times {10}^{-4}}=0.03\text{m}=3\text{cm}$