CERTIFICATION EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) Q&A 2026 |INSTANT
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1. Which component is primarily used to maintain pressure in
a water distribution system?
A. Sedimentation basin
B. Booster pump
C. Chlorinator
D. Flocculation tank
Rationale: Booster pumps increase and stabilize pressure in
distribution networks.
Correct Answer: B. Booster pump
2. What is the main purpose of residual chlorine in drinking
water systems?
A. Improve taste
B. Maintain disinfection in the distribution system
C. Increase pH
D. Remove turbidity
Rationale: Residual chlorine ensures continued microbial
protection after treatment.
,Correct Answer: B. Maintain disinfection in the distribution
system
3. Which pipe material is most commonly used in modern
water distribution systems?
A. Lead
B. Cast iron
C. PVC
D. Wood
Rationale: PVC is lightweight, corrosion-resistant, and widely
used.
Correct Answer: C. PVC
4. What does “water hammer” refer to?
A. Chemical reaction in pipes
B. Sudden pressure surge in pipes
C. Pipe corrosion
D. Water freezing in pipes
Rationale: Water hammer is caused by sudden valve closure or
pump stoppage.
Correct Answer: B. Sudden pressure surge in pipes
5. What is the main purpose of a fire hydrant in a distribution
system?
,A. Water treatment
B. Emergency water supply for firefighting
C. Water storage
D. Pressure reduction
Rationale: Fire hydrants provide access to pressurized water for
fire control.
Correct Answer: B. Emergency water supply for firefighting
6. Which factor most directly affects water flow in a pipe?
A. Pipe color
B. Pipe diameter
C. Water taste
D. Chlorine level
Rationale: Larger diameter increases flow capacity.
Correct Answer: B. Pipe diameter
7. What is the function of a backflow preventer?
A. Increase water pressure
B. Prevent reverse flow contamination
C. Filter sediment
D. Measure flow rate
Rationale: It prevents contaminated water from entering clean
water lines.
Correct Answer: B. Prevent reverse flow contamination
, 8. Which unit is commonly used to measure water pressure?
A. Liters per minute
B. Pounds per square inch (psi)
C. Cubic meters
D. Milligrams per liter
Rationale: PSI is standard for pressure measurement.
Correct Answer: B. Pounds per square inch (psi)
9. What is the purpose of flushing water mains?
A. Increase chlorine demand
B. Remove sediment and stagnant water
C. Reduce pipe size
D. Increase turbidity
Rationale: Flushing improves water quality by clearing debris.
Correct Answer: B. Remove sediment and stagnant water
10. What does turbidity measure in water?
A. Temperature
B. Cloudiness caused by particles
C. pH level
D. Hardness