AL REF Refrigeration Contractor Exam —
Practice Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. What is the primary function of a refrigeration compressor?
A. Remove moisture from the refrigerant
B. Raise the pressure and temperature of the refrigerant vapor
C. Reduce condenser pressure
D. Meter liquid refrigerant into the evaporator
Answer: B. Raise the pressure and temperature of the refrigerant vapor
Rationale: The compressor raises low-pressure vapor to a higher pressure
and temperature so the refrigerant can reject heat in the condenser.
2. Which component removes heat from the refrigerated space?
,A. Condenser
B. Compressor
C. Evaporator
D. Receiver
Answer: C. Evaporator
Rationale: The evaporator absorbs heat from the refrigerated space as
refrigerant changes from liquid to vapor.
3. What is the primary purpose of a condenser?
A. Absorb heat from the box
B. Meter refrigerant
C. Reject heat from the refrigerant
D. Increase suction pressure
Answer: C. Reject heat from the refrigerant
Rationale: The condenser removes heat from the refrigerant and changes
high-pressure vapor into liquid.
4. What happens to refrigerant pressure across a properly operating
expansion device?
A. It increases substantially
B. It remains constant
,C. It decreases
D. It becomes atmospheric
Answer: C. It decreases
Rationale: The expansion device creates a pressure drop that allows the
liquid refrigerant to enter the evaporator at a lower saturation
temperature.
5. What is superheat?
A. Temperature below saturation
B. Pressure above design pressure
C. Temperature of vapor above its saturation temperature
D. Temperature of liquid below freezing
Answer: C. Temperature of vapor above its saturation temperature
Rationale: Superheat is the amount by which a vapor's actual temperature
exceeds its saturation temperature at the measured pressure.
6. What is subcooling?
A. Heating vapor above saturation
B. Cooling liquid below its saturation temperature
C. Lowering compressor oil temperature
D. Cooling the suction vapor
, Answer: B. Cooling liquid below its saturation temperature
Rationale: Subcooling indicates how far a liquid refrigerant has been
cooled below its saturation temperature at a given pressure.
7. A thermostatic expansion valve primarily controls:
A. Condenser pressure
B. Compressor speed
C. Refrigerant flow to maintain evaporator superheat
D. Receiver level
Answer: C. Refrigerant flow to maintain evaporator superheat
Rationale: A TXV modulates refrigerant flow in response to evaporator
outlet conditions, primarily superheat.
8. Which component is commonly installed in the liquid line to remove
moisture and contaminants?
A. Accumulator
B. Receiver
C. Filter-drier
D. Muffler
Answer: C. Filter-drier
Practice Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary function of a refrigeration compressor?
A. Remove moisture from the refrigerant
B. Raise the pressure and temperature of the refrigerant vapor
C. Reduce condenser pressure
D. Meter liquid refrigerant into the evaporator
Answer: B. Raise the pressure and temperature of the refrigerant vapor
Rationale: The compressor raises low-pressure vapor to a higher pressure
and temperature so the refrigerant can reject heat in the condenser.
2. Which component removes heat from the refrigerated space?
,A. Condenser
B. Compressor
C. Evaporator
D. Receiver
Answer: C. Evaporator
Rationale: The evaporator absorbs heat from the refrigerated space as
refrigerant changes from liquid to vapor.
3. What is the primary purpose of a condenser?
A. Absorb heat from the box
B. Meter refrigerant
C. Reject heat from the refrigerant
D. Increase suction pressure
Answer: C. Reject heat from the refrigerant
Rationale: The condenser removes heat from the refrigerant and changes
high-pressure vapor into liquid.
4. What happens to refrigerant pressure across a properly operating
expansion device?
A. It increases substantially
B. It remains constant
,C. It decreases
D. It becomes atmospheric
Answer: C. It decreases
Rationale: The expansion device creates a pressure drop that allows the
liquid refrigerant to enter the evaporator at a lower saturation
temperature.
5. What is superheat?
A. Temperature below saturation
B. Pressure above design pressure
C. Temperature of vapor above its saturation temperature
D. Temperature of liquid below freezing
Answer: C. Temperature of vapor above its saturation temperature
Rationale: Superheat is the amount by which a vapor's actual temperature
exceeds its saturation temperature at the measured pressure.
6. What is subcooling?
A. Heating vapor above saturation
B. Cooling liquid below its saturation temperature
C. Lowering compressor oil temperature
D. Cooling the suction vapor
, Answer: B. Cooling liquid below its saturation temperature
Rationale: Subcooling indicates how far a liquid refrigerant has been
cooled below its saturation temperature at a given pressure.
7. A thermostatic expansion valve primarily controls:
A. Condenser pressure
B. Compressor speed
C. Refrigerant flow to maintain evaporator superheat
D. Receiver level
Answer: C. Refrigerant flow to maintain evaporator superheat
Rationale: A TXV modulates refrigerant flow in response to evaporator
outlet conditions, primarily superheat.
8. Which component is commonly installed in the liquid line to remove
moisture and contaminants?
A. Accumulator
B. Receiver
C. Filter-drier
D. Muffler
Answer: C. Filter-drier
