AZ L-91 Irrigation Systems Contractor
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. What is the primary purpose of an irrigation system?
A. To increase soil compaction
B. To deliver water to plants in a controlled manner
C. To eliminate the need for drainage
D. To replace all natural rainfall
Answer: B. To deliver water to plants in a controlled manner
Rationale: An irrigation system is designed to apply water to landscaped or
agricultural areas at controlled rates and times to meet plant-water
requirements efficiently.
2. Which component controls the flow of water to an individual irrigation
zone?
, A. Pressure gauge
B. Solenoid valve
C. Pipe sleeve
D. Emitter
Answer: B. Solenoid valve
Rationale: A solenoid-operated control valve opens and closes
automatically in response to an irrigation controller.
3. What is the purpose of an irrigation controller?
A. Increase pipe diameter
B. Schedule irrigation events
C. Filter sand from soil
D. Increase water temperature
Answer: B. Schedule irrigation events
Rationale: The controller activates irrigation valves according to
programmed watering schedules and durations.
4. Which device helps prevent contaminated irrigation water from
flowing backward into a potable water supply?
A. Pressure regulator
B. Backflow preventer
, C. Flow sensor
D. Check valve on a sprinkler
Answer: B. Backflow preventer
Rationale: Backflow prevention devices protect potable water supplies
from possible contamination caused by backpressure or backsiphonage.
5. What does a pressure regulator do?
A. Raises water pressure indefinitely
B. Reduces excessive downstream pressure
C. Removes chlorine from water
D. Measures precipitation
Answer: B. Reduces excessive downstream pressure
Rationale: Pressure regulators maintain a controlled downstream pressure
when supply pressure is higher than the irrigation components require.
6. Which irrigation method generally applies water directly to the root
zone through small emitters?
A. Flood irrigation
B. Drip irrigation
C. Spray irrigation
D. Furrow irrigation
Answer: B. Drip irrigation
, Rationale: Drip irrigation delivers water slowly and directly near plant
roots, reducing evaporation and runoff when properly designed and
maintained.
7. What is precipitation rate?
A. The amount of fertilizer applied
B. The rate at which irrigation water is applied to an area
C. The water pressure at the meter
D. The flow through a backflow preventer
Answer: B. The rate at which irrigation water is applied to an area
Rationale: Precipitation rate describes how quickly water is applied over a
given landscape area, commonly expressed in inches per hour.
8. What is the most important reason to zone an irrigation system?
A. To eliminate valves
B. To allow different areas to be watered according to their hydraulic
and plant requirements
C. To increase pipe friction
D. To prevent controller programming
Answer: B. To allow different areas to be watered according to their
hydraulic and plant requirements
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary purpose of an irrigation system?
A. To increase soil compaction
B. To deliver water to plants in a controlled manner
C. To eliminate the need for drainage
D. To replace all natural rainfall
Answer: B. To deliver water to plants in a controlled manner
Rationale: An irrigation system is designed to apply water to landscaped or
agricultural areas at controlled rates and times to meet plant-water
requirements efficiently.
2. Which component controls the flow of water to an individual irrigation
zone?
, A. Pressure gauge
B. Solenoid valve
C. Pipe sleeve
D. Emitter
Answer: B. Solenoid valve
Rationale: A solenoid-operated control valve opens and closes
automatically in response to an irrigation controller.
3. What is the purpose of an irrigation controller?
A. Increase pipe diameter
B. Schedule irrigation events
C. Filter sand from soil
D. Increase water temperature
Answer: B. Schedule irrigation events
Rationale: The controller activates irrigation valves according to
programmed watering schedules and durations.
4. Which device helps prevent contaminated irrigation water from
flowing backward into a potable water supply?
A. Pressure regulator
B. Backflow preventer
, C. Flow sensor
D. Check valve on a sprinkler
Answer: B. Backflow preventer
Rationale: Backflow prevention devices protect potable water supplies
from possible contamination caused by backpressure or backsiphonage.
5. What does a pressure regulator do?
A. Raises water pressure indefinitely
B. Reduces excessive downstream pressure
C. Removes chlorine from water
D. Measures precipitation
Answer: B. Reduces excessive downstream pressure
Rationale: Pressure regulators maintain a controlled downstream pressure
when supply pressure is higher than the irrigation components require.
6. Which irrigation method generally applies water directly to the root
zone through small emitters?
A. Flood irrigation
B. Drip irrigation
C. Spray irrigation
D. Furrow irrigation
Answer: B. Drip irrigation
, Rationale: Drip irrigation delivers water slowly and directly near plant
roots, reducing evaporation and runoff when properly designed and
maintained.
7. What is precipitation rate?
A. The amount of fertilizer applied
B. The rate at which irrigation water is applied to an area
C. The water pressure at the meter
D. The flow through a backflow preventer
Answer: B. The rate at which irrigation water is applied to an area
Rationale: Precipitation rate describes how quickly water is applied over a
given landscape area, commonly expressed in inches per hour.
8. What is the most important reason to zone an irrigation system?
A. To eliminate valves
B. To allow different areas to be watered according to their hydraulic
and plant requirements
C. To increase pipe friction
D. To prevent controller programming
Answer: B. To allow different areas to be watered according to their
hydraulic and plant requirements
