13. Water rises in a capillary tube when its one end is dipped vertically

Water rises in a capillary tube when its one end is dipped vertically in it, is 3 cm. If the surface tension of water is 75 × 10^-3 N/m, then the diameter of capillary will be

(a)   0.1 mm                                     

(b)  0.5 mm

(c)   1.0 mm                             

(d)  2.0 mm

Ans. c