Pumping Systems MCQs – T4Tutorials .PK

25 Score: 0 Attempted: 0/25 Subscribe

1. : A pump is a device that converts:
(A) Hydraulic energy to mechanical energy
(B) Electrical energy to hydraulic energy
(C) Mechanical energy to hydraulic energy
(D) Solar energy to kinetic energy

2. : The net positive suction head (NPSH) is related to:
(A) Pump speed
(B) Avoiding cavitation
(C) Efficiency of motor
(D) Diameter of impeller only

3. : The efficiency of a pump is the ratio of:
(A) Output power to input power
(B) Input power to output power
(C) Discharge to suction
(D) Velocity head to pressure head

4. : Cavitation in pumps is caused by:
(A) High discharge pressure
(B) Vaporization of liquid at low pressure
(C) Excessive lubrication
(D) Pump priming

5. : The discharge of a centrifugal pump is directly proportional to:
(A) Diameter of impeller
(B) Square of impeller speed
(C) Head developed
(D) Pipe length

6. : The total head against which a pump works is equal to:
(A) Static head + velocity head
(B) Static head + friction head + velocity head
(C) Suction head only
(D) Discharge head only

7. : The suction lift of a centrifugal pump is limited mainly by:
(A) Cavitation and atmospheric pressure
(B) Diameter of delivery pipe
(C) Pump efficiency
(D) Length of shaft

8. : Priming of a centrifugal pump is done to:
(A) Increase efficiency
(B) Fill casing and suction pipe with water to remove air
(C) Increase discharge
(D) Cool the pump motor

9. : A reciprocating pump is best suited for:
(A) Large discharge and low head
(B) Small discharge and high head
(C) Low discharge and low head
(D) High discharge and medium head

10. : Centrifugal pumps are preferred for irrigation because:
(A) They are cheaper and handle large discharge
(B) They require no priming
(C) They work at very high heads
(D) They consume less power always

11. : The efficiency of a pump-motor unit is equal to:
(A) Pump efficiency × Motor efficiency
(B) Pump efficiency + Motor efficiency
(C) Pump efficiency ÷ Motor efficiency
(D) Motor efficiency ÷ Pump efficiency

12. : The power required to operate a pump is proportional to:
(A) Discharge × Head
(B) Head ÷ Discharge
(C) Square of discharge
(D) Square of head

13. : The specific speed of a pump is defined as speed at which pump develops:
(A) 1 unit discharge under 1 unit head
(B) 1 unit discharge under unit power
(C) 1 unit discharge under 100 m head
(D) Unit power under unit speed

14. : The type of pump used for lifting water directly from canals or rivers with low head is:
(A) Jet pump
(B) Axial flow pump
(C) Reciprocating pump
(D) Air-lift pump

15. : Jet pumps are operated by:
(A) Compressed air
(B) High-velocity jet of water
(C) Hydraulic turbine
(D) Electric motor

16. : Submersible pumps are widely used because:
(A) They do not require priming
(B) Motor and pump are placed underwater
(C) Suitable for deep tube wells
(D) All of the above

17. : The maximum suction lift in practice for centrifugal pumps is about:
(A) 2–3 m
(B) 5–6 m
(C) 8–9 m
(D) 15 m

18. : A pump characteristic curve represents relationship between:
(A) Head, discharge, and efficiency
(B) Discharge and velocity
(C) Head and suction lift only
(D) Efficiency and motor speed only

19. : The speed at which a centrifugal pump operates without delivering water is called:
(A) Normal speed
(B) Shut-off speed
(C) Priming speed
(D) Air-binding speed

20. : The efficiency of reciprocating pumps is usually:
(A) 30–40%
(B) 50–60%
(C) 70–80%
(D) 85–95%

21. : In pumps, slip is defined as:
(A) Difference between theoretical discharge and actual discharge
(B) Difference between suction head and delivery head
(C) Head loss due to friction
(D) Ratio of velocity to discharge

22. : The unit in which pump power is usually expressed in irrigation engineering is:
(A) Watt
(B) Kilowatt
(C) Horsepower
(D) Joule

23. : The efficiency of centrifugal pumps decreases mainly due to:
(A) Friction losses and recirculation losses
(B) High impeller speed only
(C) Priming
(D) Small suction lift

24. : The total dynamic head (TDH) of a pump includes:
(A) Static head only
(B) Static head + friction losses + velocity head
(C) Friction losses only
(D) Suction lift only

25. : The most energy-efficient irrigation pumping system is:
(A) Centrifugal pump with low efficiency motor
(B) Diesel engine pump with high load factor
(C) Submersible pump with high-efficiency motor
(D) Jet pump with compressed air