Question

If two identical pumps each capable to deliver a discharge Q against a head H are connected ___________________________

(a) in parallel, the resulting discharge is 2Q against a head H

(b) in parallel, the resulting discharge is Q against a head of 2H

(c) in series, the resulting discharge is 2Q against a head H

(d) in series, the resulting discharge is Q against a head 2H

The question was asked during an online interview.

Enquiry is from Hydro Electric Power in portion Hydro Electric Power of Irrigation Engineering

Answer 1

Right choice is (a) in parallel, the resulting discharge is 2Q against a head H

To explain: Water pumps are installed in parallel as in the case of pumping water from a sump well using more than one pump. The head remains constant and the combined discharge of the two pumps is equal to the sum of the individual discharges for a specific head.