Question

The head loss at the entrance of the pipe is that at it’s exit

(a) equal to

(b) half

(c) twice

(d) four times

The question was posed to me by my college director while I was bunking the class.

I want to ask this question from Loss of Energy in Pipes in portion Flow Through Pipes of Fluid Mechanics

Answer 1

The correct option is (b) half

For explanation I would say: According to Darcy-Weisbach’s formula,

hi = o.5v^2 / 2g and ho = v^2 / 2g, where hi is the head loss at pipe entrance, ho is the head loss at pipe exit and v is the flow velocity. Thus hi = 0.5ho.