55. Two capillary tubes of the same length but different radii
r1 and r2 are fitted in parallel to the bottom of a vessel. The pressure head is P. What should be the radius of a single tube that can replace the two tubes so that the rate of flow is same as before
(a) r1 + r2 (b) r1 2 + r2 2
(c) r14 + r2 4 (d) None of these
Answer-d
(9)