Question

When a liquid is taken in a capillary tube, flat meniscus is observed. Choose the correct option.

• A. Angle of contact is ${90}^{\circ }$
• B. Cohesive forces between liquid molecules is greater than the adhesive forces between liquid molecules and glass
• C. Cohesive forces between liquid molecules is less than the adhesive forces between liquid molecules and glass.
• D. None of these

Answer 1

The correct option is A Angle of contact is ${90}^{\circ }$


We know,
When $F_{\text{adhesive}}=F_{cohesive}$
Flat meniscus is observed.
Also,
Angle of contact, $\theta ={90}^{\circ }$
So, option (a) are correct.