question_answer

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

A)  rh = constant   

B) \[\frac{h}{r}=\] constant

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  = constant ie, lesser the radius of capillary greater will be the rise and vice-versa.