Question

Water rises in a capillary upto a height h. If now this capillary is tilted by an angle of ${45}^{\circ }$, then the length of the water column in the capillary becomes

• A. 2h
• B. $\frac{h}{2}$
• C. $\frac{h}{\sqrt{2}}$
• D. $h\sqrt{2}$

Answer 1

Answer: (C)

$\frac{h}{\sqrt{2}}$

The expression for the capillary rise in a tube is given by,

H = $\frac{2Tcos\theta }{\rho gr}$

for all other parameters kept constant, if I change the angle of inclination to ${45}^o$

$cos\theta$ will go from 1 to $\frac{1}{\sqrt{2}}$

Therefore, the height of capillary tube rise will also change from $Hto\frac{H}{\sqrt{2}}$