Question

Water rises upto a height $\text{h}$ in a capillary tube of certain diameter. This capillary tube is replaced by a similar tube of half the diameter. Now water will rise to a height of

• A. $\text{4h}$
• B. $\text{3h}$
• C. $\text{2h}$
• D. $\frac{\text{h}}{2}$

Answer 1

Answer: (C)

From capillary tube experiment, We know that
$\text{h}=\frac{2\text{Scos}\theta }{\text{r}\text{ρ}\text{g}}\text{i.e.}\text{h}\propto \frac{1}{\text{r}}$
$\therefore \frac{{\text{h}}^{{}^{\prime }}}{\text{h}}=\frac{\text{r}}{\text{r/}2}=2\text{or}{\text{h}}^{{}^{\prime }}=2\text{h}$