question_answer

For different capillaries of radius r, the condition of liquid rise (h) to surface tension is

A)  \[rh=\] constant             

B)                                        \[\frac{h}{r}=cons\tan t\]            

C)                         h + r = constant               

D)                        h - r = constant

Correct Answer: A

Solution :

Capillary rise \[h=\frac{2T\cos \theta }{\rho rg}.\]For a given liquid and solid at a given place as \[\rho ,T,\theta \]and g are constant. \[\therefore \]  \[hr=\text{constant}\] ie, lesser the radius of capillary greater will be the rise and vice-versa.