Question

A capillary tube $A$ is dipped in water. Another identical tube $B$ is dipped in a soap - water solution. Which of the following shows the relative nature of the liquid columns in the two tubes?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

Soap solution has lower surface tension $\left(T\right)$ as compared to pure water and capillary rise $h=\frac{2T\text{cos}\theta }{\rho rg}$, so $h$ is less for soap solution.
Therefore rise of soap solution in the capillary tube is less as compared to water.