AZ ROC – CR-38 HVACR Contractor
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
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1. What is the primary purpose of a refrigeration system in an HVACR
application?
A. To generate heat directly
B. To circulate indoor air only
C. To transfer heat from a lower-temperature area to a higher-
temperature area
D. To increase humidity
Rationale: A refrigeration system does not create “cold.” It removes
heat from a conditioned space or product and rejects that heat to
another location, such as outdoor air. This heat-transfer process is the
foundation of air conditioning and refrigeration.
,2. Which component removes heat from the conditioned space in a
typical split-system air conditioner?
A. Condenser
B. Compressor
C. Expansion valve
D. Evaporator
Rationale: The evaporator absorbs heat from the indoor air as
refrigerant evaporates inside its coil. The condenser then rejects that
absorbed heat outdoors.
3. What is the primary function of the compressor?
A. Lower refrigerant pressure
B. Remove moisture from indoor air
C. Raise the pressure and temperature of refrigerant vapor
D. Meter liquid refrigerant into the condenser
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. This allows the refrigerant to reject heat in the
condenser.
,4. What is the main purpose of a condenser coil?
A. Absorb heat from indoor air
B. Meter refrigerant flow
C. Reject heat from the refrigerant to the surrounding environment
D. Separate oil from refrigerant
Rationale: In the condenser, hot high-pressure refrigerant vapor
releases heat to outdoor air or another cooling medium and changes
into a liquid.
5. What does the metering device primarily control?
A. Compressor oil level
B. Condenser fan speed
C. The amount of refrigerant entering the evaporator
D. Supply-air temperature directly
Rationale: A metering device creates a pressure drop and regulates
refrigerant flow into the evaporator. Proper metering is necessary for
correct evaporator performance and superheat.
6. Which refrigerant condition normally exists at the compressor inlet
in a properly operating comfort-cooling system?
, A. High-pressure liquid
B. Low-pressure liquid
C. High-pressure vapor
D. Low-pressure vapor
Rationale: The evaporator should boil the refrigerant and produce
vapor before it reaches the compressor. Compressors are designed
primarily to compress vapor, not liquid.
7. What is compressor slugging?
A. Excessive condenser airflow
B. Insufficient refrigerant charge
C. Liquid refrigerant entering the compressor
D. Excessive evaporator superheat
Rationale: Liquid entering a compressor can cause severe mechanical
damage because liquids are essentially incompressible. Slugging may
result from overfeeding the evaporator, improper superheat, flooding,
or other system problems.
8. What does superheat represent?
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of a refrigeration system in an HVACR
application?
A. To generate heat directly
B. To circulate indoor air only
C. To transfer heat from a lower-temperature area to a higher-
temperature area
D. To increase humidity
Rationale: A refrigeration system does not create “cold.” It removes
heat from a conditioned space or product and rejects that heat to
another location, such as outdoor air. This heat-transfer process is the
foundation of air conditioning and refrigeration.
,2. Which component removes heat from the conditioned space in a
typical split-system air conditioner?
A. Condenser
B. Compressor
C. Expansion valve
D. Evaporator
Rationale: The evaporator absorbs heat from the indoor air as
refrigerant evaporates inside its coil. The condenser then rejects that
absorbed heat outdoors.
3. What is the primary function of the compressor?
A. Lower refrigerant pressure
B. Remove moisture from indoor air
C. Raise the pressure and temperature of refrigerant vapor
D. Meter liquid refrigerant into the condenser
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor. This allows the refrigerant to reject heat in the
condenser.
,4. What is the main purpose of a condenser coil?
A. Absorb heat from indoor air
B. Meter refrigerant flow
C. Reject heat from the refrigerant to the surrounding environment
D. Separate oil from refrigerant
Rationale: In the condenser, hot high-pressure refrigerant vapor
releases heat to outdoor air or another cooling medium and changes
into a liquid.
5. What does the metering device primarily control?
A. Compressor oil level
B. Condenser fan speed
C. The amount of refrigerant entering the evaporator
D. Supply-air temperature directly
Rationale: A metering device creates a pressure drop and regulates
refrigerant flow into the evaporator. Proper metering is necessary for
correct evaporator performance and superheat.
6. Which refrigerant condition normally exists at the compressor inlet
in a properly operating comfort-cooling system?
, A. High-pressure liquid
B. Low-pressure liquid
C. High-pressure vapor
D. Low-pressure vapor
Rationale: The evaporator should boil the refrigerant and produce
vapor before it reaches the compressor. Compressors are designed
primarily to compress vapor, not liquid.
7. What is compressor slugging?
A. Excessive condenser airflow
B. Insufficient refrigerant charge
C. Liquid refrigerant entering the compressor
D. Excessive evaporator superheat
Rationale: Liquid entering a compressor can cause severe mechanical
damage because liquids are essentially incompressible. Slugging may
result from overfeeding the evaporator, improper superheat, flooding,
or other system problems.
8. What does superheat represent?
