A centrifugal pump has a impeller of 30 cm diameter and runs at 1000 rpm giving best efficiency. It delivered 1.2 m3/minute against a head of 25 m. What is its non-dimensional specific speed (based on flow expressed in l.p.s.)?
[Take √9.81 = 3.132; and √√9.81 = 1.77]
1
55
2
63
3
72
4
80