Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
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1. What is the primary purpose of a centrifugal pump in a water
system?
a. Increase water temperature
b. Increase water pressure and flow
c. Filter water
d. Measure water quality
The centrifugal pump converts mechanical energy into fluid energy
to increase pressure and flow.
2. Which component of a pump prevents backflow when the pump
is off?
a. Impeller
b. Check valve
c. Suction strainer
d. Coupling
Check valves allow flow in one direction only, preventing reverse
flow.
3. What is the function of a pump impeller?
a. Convert electrical energy into mechanical energy
b. Transfer energy to the fluid
, c. Seal the pump casing
d. Monitor flow rate
The impeller accelerates the fluid and increases its velocity and
pressure.
4. Cavitation in a pump is caused by:
a. Excessive motor speed
b. Low suction pressure leading to vapor formation
c. Overheating of bearings
d. High discharge pressure
Cavitation occurs when the liquid vaporizes due to low pressure at
the pump suction.
5. Which measurement indicates the pump’s ability to lift water from
a source?
a. Flow rate
b. Efficiency
c. Suction head
d. Discharge head
Suction head represents the vertical distance the pump can draw
water from the source.
6. What is the typical unit for measuring pump flow?
a. PSI
b. GPM (gallons per minute)
c. RPM
d. Feet of head
Pump flow is usually expressed in gallons per minute (GPM).
7. Which type of pump is most commonly used in water distribution
systems?
, a. Reciprocating pump
b. Gear pump
c. Centrifugal pump
d. Diaphragm pump
Centrifugal pumps are widely used due to simplicity, efficiency, and
suitability for large flows.
8. What is the main purpose of a pump seal?
a. Increase flow
b. Prevent leakage
c. Measure pressure
d. Reduce noise
Seals prevent fluid from leaking along the pump shaft.
9. Which condition can cause pump overheating?
a. Excessive flow
b. Running the pump dry
c. Proper alignment
d. Correct voltage supply
Running a pump without fluid prevents heat dissipation, causing
overheating.
10. A pump operating point where flow is zero is called:
a. Shutoff head
b. Maximum flow
c. Deadhead
d. NPSH
Deadhead occurs when a pump is running against a closed
discharge valve.