Question

Water rises to a height of 20 mm in a capillary if the radius of the capillary is made one third of its previous value then what is the new value of the capillary rise?

Answer 1

Since `h=(2Tcostheta)/(rdg)` and the same liquid and capillaries of difference radii `h_(1)r_(1)=h_(2)r_(2)`
`therefore(h_(2))/(h_(1))=(r_(1))/(r_(2))=(1)/((1//3))=3` hence `h_(2)=3h_(1)=3xx20mm=60mm`