A runner of a centrifugal pump has an outer diameter of 25 cm and runs at 1500 rpm. It has 10 blades, each of 5 mm thickness. They are backward facing at 30° to the tangent and the breadth of the flow passages at outlet is 12.5 mm. Pressure gauges are fitted close to the pump casing on the suction and discharge pipes, both are 2.5 m above water level in supply sump. When discharge is 26 lit/s, the gauge readings are 4m vacuum and 16.5 m of water respectively. Assume that there is no whirl at inlet and no whirl slip. If 50% of velocity head at outlet from the runner is recovered as static head in the volute, estimate:
(i) Theoretical head
(ii) Manometric efficiency
(iii) Losses in the impeller, and
(iv) Capacity of the motor to drive the pump, if mechanical efficiency is 0.9