Question

A glass capillary tube is lowered vertically into liquid in a vessel.
Match the column
$\begin{array}{cc}\text{Column 1}& \text{Column 2}\\ \text{Contact angle}& \text{Liquid level in capillary tube}\\ A)\theta <{90}^{\circ }& \text{(i) Ascends}\\ B)\theta >{90}^{\circ }& \text{(ii) Descends}\\ C)\theta =0^{\circ }& \text{(iii) Neither ascends nor descends}\end{array}$

• A. $A\to \left(ii\right);B\to \left(i\right);C\to \left(iii\right)$
• B. $A\to \left(i\right);B\to \left(ii\right);C\to \left(iii\right)$
• C. $A\to \left(iii\right);B\to \left(i\right);C\to \left(ii\right)$
• D. None of these

Answer 1

The correct option is B $A\to \left(i\right);B\to \left(ii\right);C\to \left(iii\right)$

We know,
The rise or fall of liquid in capillary depend on the relative magnitude of the cohesion and the adhesion of the liquids to the walls of the capillary tube and hence to contact angle $\left(\theta \right)$.
If $\theta <{90}^{\circ }$, liquid will ascend in capillary tube.
If $\theta ={90}^{\circ }$, liquid will neither ascend nor descend in capillary tube.
If $\theta >{90}^{\circ }$, liquid will descend in capillary tube.