LARE LARE Irrigation Design 3

Question 1

Which formula correctly calculates precipitation rate (PR) in inches per hour for a sprinkler zone?

Accepted Answer

PR = (96.25 × GPM) ÷ Area (sq ft)

Answer

PR = Flow rate (GPM) × Head spacing (ft)

Answer

PR = PSI ÷ GPM

Answer

PR = Head spacing (ft) ÷ Flow rate (GPM)

Question 2

Which backflow preventer assembly provides the highest level of protection and is required for high-hazard irrigation connections?

Accepted Answer

Reduced pressure zone assembly (RPZ)

Answer

Pressure vacuum breaker (PVB)

Answer

Double check valve assembly (DCVA)

Answer

Atmospheric vacuum breaker (AVB)

Question 3

What does ET₀ (reference evapotranspiration) represent in irrigation science?

Accepted Answer

Evapotranspiration from a standardized hypothetical grass reference surface used as a baseline

Answer

Estimated transpiration from a specific turf species only

Answer

Total evaporation measured from open water surfaces at a site

Answer

Minimum daily water requirement for established trees

Question 4

Which soil amendment most effectively improves water retention in sandy soils?

Accepted Answer

Organic compost

Answer

Perlite

Answer

Coarse gravel

Answer

Additional sand

Question 5

What is the primary function of a flow sensor connected to an irrigation controller?

Accepted Answer

To detect abnormal flow rates from pipe breaks or stuck valves and signal the controller to shut down the master valve

Answer

To measure total water consumption for utility billing

Answer

To regulate and equalize flow rate to each zone valve

Answer

To convert line pressure to a flow velocity signal

Question 6

Which factor most directly determines the throw radius of a sprinkler head?

Accepted Answer

Operating pressure at the head

Answer

Nozzle color code

Answer

Time of day irrigation runs

Answer

Surrounding soil texture

Question 7

What is the correct sequence of components from the water meter to the irrigation zone valve in a properly designed system?

Accepted Answer

Meter → backflow preventer → master valve → filter → zone valve

Answer

Meter → zone valve → backflow preventer → master valve → filter

Answer

Meter → filter → zone valve → backflow preventer → master valve

Answer

Meter → master valve → zone valve → filter → backflow preventer