The ratio h2/h1 is

Question

The head loss for a laminar incompressible flow through a horizontal circular pipe is h₁ Pipe length and fluid remaining the same, if the average flow velocity doubles and the pipe diameter reduces to half its previous value, the head loss is h₂. The ratio h₂/h₁ is                                                                                              

      (a) 1                                (b) 4                             (c) 8                                (d) 16