Apprentice Refrigeration Technician
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1.A refrigeration system uses a compressor to increase the pressure and
temperature of the refrigerant vapor before it enters the condenser. Which
component function is being described?
A. Expansion valve operation
B. Evaporator heat absorption
C. Compressor vapor compression
D. Receiver liquid storage
Correct Answer: C. Compressor vapor compression
The compressor raises the refrigerant vapor pressure and temperature by
compressing low-pressure vapor from the evaporator into high-pressure
vapor that can release heat in the condenser.
2. In a standard vapor-compression refrigeration cycle, what is the
primary purpose of the condenser?
A. To absorb heat from the conditioned space
B. To reject heat from the refrigerant to the surrounding environment
C. To reduce refrigerant pressure rapidly
D. To separate oil from refrigerant vapor
,Correct Answer: B. To reject heat from the refrigerant to the surrounding
environment
The condenser removes heat from the high-pressure refrigerant vapor,
causing it to condense into a high-pressure liquid before entering the
expansion device.
3. Which refrigerant characteristic is most important for efficient heat
transfer in a refrigeration system?
A. High thermal conductivity
B. High electrical resistance
C. Low vapor density only
D. Ability to absorb moisture
Correct Answer: A. High thermal conductivity
Good thermal conductivity allows the refrigerant to efficiently absorb and
reject heat during phase changes within the refrigeration cycle.
4. What is the main function of an evaporator in a refrigeration system?
A. Compress refrigerant vapor
B. Remove heat from the refrigerated space
C. Increase refrigerant pressure
D. Store excess liquid refrigerant
Correct Answer: B. Remove heat from the refrigerated space
The evaporator absorbs heat from the surrounding area as the refrigerant
changes from a low-pressure liquid mixture into vapor.
5. A refrigeration technician measures superheat at the evaporator
outlet. What does superheat indicate?
A. The amount of liquid refrigerant entering the compressor
B. The temperature increase of refrigerant vapor above its saturation
,temperature
C. The pressure drop across the condenser
D. The amount of oil inside the compressor
Correct Answer: B. The temperature increase of refrigerant vapor above its
saturation temperature
Superheat measures how much the vapor temperature exceeds the
refrigerant’s boiling point at a given pressure and helps ensure liquid
refrigerant does not reach the compressor.
6. What is the purpose of an expansion valve in a refrigeration system?
A. Increase refrigerant pressure
B. Remove heat from the condenser
C. Reduce refrigerant pressure and control flow into the evaporator
D. Compress refrigerant vapor
Correct Answer: C. Reduce refrigerant pressure and control flow into the
evaporator
The expansion valve creates a pressure drop that lowers refrigerant
temperature while regulating the amount of refrigerant entering the
evaporator.
7. Which tool is commonly used to measure refrigerant pressure during
servicing?
A. Multimeter
B. Manifold gauge set
C. Clamp meter
D. Micrometer
Correct Answer: B. Manifold gauge set
A manifold gauge set allows technicians to monitor suction and discharge
pressures for diagnosing refrigeration system operation.
, 8. What condition can occur if liquid refrigerant enters the compressor?
A. Improved lubrication
B. Increased compression efficiency
C. Compressor damage due to liquid slugging
D. Lower refrigerant temperature only
Correct Answer: C. Compressor damage due to liquid slugging
Compressors are designed to compress vapor, not liquid, and liquid
slugging can cause severe mechanical damage to compressor components.
9. Which refrigerant component changes low-pressure liquid refrigerant
into low-pressure vapor?
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
Correct Answer: B. Evaporator
The evaporator absorbs heat from the surroundings, causing the
refrigerant to boil and change into vapor.
10. What is the purpose of a filter-drier in a refrigeration system?
A. Increase refrigerant pressure
B. Remove moisture and contaminants
C. Increase compressor speed
D. Measure refrigerant temperature
Correct Answer: B. Remove moisture and contaminants
A filter-drier protects the refrigeration system by absorbing moisture and
trapping debris that could damage components or cause blockages.
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1.A refrigeration system uses a compressor to increase the pressure and
temperature of the refrigerant vapor before it enters the condenser. Which
component function is being described?
A. Expansion valve operation
B. Evaporator heat absorption
C. Compressor vapor compression
D. Receiver liquid storage
Correct Answer: C. Compressor vapor compression
The compressor raises the refrigerant vapor pressure and temperature by
compressing low-pressure vapor from the evaporator into high-pressure
vapor that can release heat in the condenser.
2. In a standard vapor-compression refrigeration cycle, what is the
primary purpose of the condenser?
A. To absorb heat from the conditioned space
B. To reject heat from the refrigerant to the surrounding environment
C. To reduce refrigerant pressure rapidly
D. To separate oil from refrigerant vapor
,Correct Answer: B. To reject heat from the refrigerant to the surrounding
environment
The condenser removes heat from the high-pressure refrigerant vapor,
causing it to condense into a high-pressure liquid before entering the
expansion device.
3. Which refrigerant characteristic is most important for efficient heat
transfer in a refrigeration system?
A. High thermal conductivity
B. High electrical resistance
C. Low vapor density only
D. Ability to absorb moisture
Correct Answer: A. High thermal conductivity
Good thermal conductivity allows the refrigerant to efficiently absorb and
reject heat during phase changes within the refrigeration cycle.
4. What is the main function of an evaporator in a refrigeration system?
A. Compress refrigerant vapor
B. Remove heat from the refrigerated space
C. Increase refrigerant pressure
D. Store excess liquid refrigerant
Correct Answer: B. Remove heat from the refrigerated space
The evaporator absorbs heat from the surrounding area as the refrigerant
changes from a low-pressure liquid mixture into vapor.
5. A refrigeration technician measures superheat at the evaporator
outlet. What does superheat indicate?
A. The amount of liquid refrigerant entering the compressor
B. The temperature increase of refrigerant vapor above its saturation
,temperature
C. The pressure drop across the condenser
D. The amount of oil inside the compressor
Correct Answer: B. The temperature increase of refrigerant vapor above its
saturation temperature
Superheat measures how much the vapor temperature exceeds the
refrigerant’s boiling point at a given pressure and helps ensure liquid
refrigerant does not reach the compressor.
6. What is the purpose of an expansion valve in a refrigeration system?
A. Increase refrigerant pressure
B. Remove heat from the condenser
C. Reduce refrigerant pressure and control flow into the evaporator
D. Compress refrigerant vapor
Correct Answer: C. Reduce refrigerant pressure and control flow into the
evaporator
The expansion valve creates a pressure drop that lowers refrigerant
temperature while regulating the amount of refrigerant entering the
evaporator.
7. Which tool is commonly used to measure refrigerant pressure during
servicing?
A. Multimeter
B. Manifold gauge set
C. Clamp meter
D. Micrometer
Correct Answer: B. Manifold gauge set
A manifold gauge set allows technicians to monitor suction and discharge
pressures for diagnosing refrigeration system operation.
, 8. What condition can occur if liquid refrigerant enters the compressor?
A. Improved lubrication
B. Increased compression efficiency
C. Compressor damage due to liquid slugging
D. Lower refrigerant temperature only
Correct Answer: C. Compressor damage due to liquid slugging
Compressors are designed to compress vapor, not liquid, and liquid
slugging can cause severe mechanical damage to compressor components.
9. Which refrigerant component changes low-pressure liquid refrigerant
into low-pressure vapor?
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
Correct Answer: B. Evaporator
The evaporator absorbs heat from the surroundings, causing the
refrigerant to boil and change into vapor.
10. What is the purpose of a filter-drier in a refrigeration system?
A. Increase refrigerant pressure
B. Remove moisture and contaminants
C. Increase compressor speed
D. Measure refrigerant temperature
Correct Answer: B. Remove moisture and contaminants
A filter-drier protects the refrigeration system by absorbing moisture and
trapping debris that could damage components or cause blockages.
