The specific speed (Ns) of a centrifugal pump is given by

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Correct Answer

1. Mechanical efficiency of a centrifugal pump is the ratio of
Options
A. energy available at the impeller to the energy supplied to the pump by the prime mover
B. actual workdone by the pump to the energy supplied to the pump by the prime mover
C. energy supplied to the pump to the energy available at the impeller
D. manometric head to the energy supplied by the impeller per kN of water

Correct Answer: energy available at the impeller to the energy supplied to the pump by the prime mover

Correct Answer: two runners

3. Which of the following pump is successfully used for lifting water from deep wells?
Options
A. Centrifugal pump
B. Reciprocating pump
C. Jet pump
D. Air lift pump

Correct Answer: Air lift pump

4. The efficiency of a reaction turbine for a given head __________ with the increase in speed.
Options
A. decreases
B. increases

Correct Answer: decreases

5. The ratio of the normal force of jet of water on a plate inclined at an angle of 30� as compared to that when the plate is normal to jet, is
Options
A. 1/2
B. 1/2
C. 1
D. 2

Correct Answer: 1/2

6. Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m.?
Options
A. Pelton wheel
B. Francis turbine
C. Kaplan turbine
D. none of these

Correct Answer: Francis turbine

Correct Answer: directly proportional to H^1/2

8. The efficiency of a hydraulic press is given by (where W = Weight lifted by ram, P = Force applied on plunger, A = Area of ram, and a = Area of plunger)
Options
A.
B.
C.
D.