NL Refrigeration Mechanic Certification Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a refrigeration system?
A. Heating a space
B. Removing heat from a space
C. Producing electricity
D. Filtering air
Refrigeration systems are designed to remove heat from a space
or substance to lower its temperature.
2. Which refrigerant is considered environmentally friendly with low
ozone depletion potential?
A. R-22
B. R-134a
C. R-12
D. R-502
R-134a is a hydrofluorocarbon (HFC) that has zero ozone depletion
potential compared to older CFCs like R-12.
3. What component of a refrigeration system removes heat from the
refrigerant?
A. Compressor
B. Expansion valve
C. Condenser
, D. Evaporator
The condenser releases heat from the refrigerant into the
surrounding environment.
4. In a refrigeration cycle, the refrigerant absorbs heat in the:
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
The evaporator is where the refrigerant absorbs heat from the
space being cooled.
5. Which type of compressor is commonly used in small commercial
refrigeration systems?
A. Screw
B. Centrifugal
C. Reciprocating
D. Axial
Reciprocating compressors are widely used in small and medium
refrigeration systems due to their simplicity and efficiency.
6. What does a thermostatic expansion valve (TXV) control?
A. Compressor speed
B. Condenser fan operation
C. Refrigerant flow to the evaporator
D. System pressure
The TXV regulates the amount of refrigerant entering the
evaporator based on load conditions.
7. What is the function of an accumulator in a refrigeration system?
A. Increase system pressure
, B. Prevent liquid refrigerant from entering the compressor
C. Filter the refrigerant
D. Measure temperature
Accumulators protect compressors by ensuring only vapor enters,
preventing liquid slugging.
8. Which pressure indicates the low side of a refrigeration system?
A. Suction pressure
B. Evaporator pressure
C. Discharge pressure
D. Condenser pressure
Low-side pressure is measured at the evaporator or suction line.
9. What is the purpose of oil in a refrigeration compressor?
A. Cool the evaporator
B. Lubricate moving parts
C. Condense the refrigerant
D. Increase system pressure
Oil reduces friction and wear in the compressor moving parts.
10. Which type of refrigerant leak detector is most commonly
used for HFC refrigerants?
A. Halide torch
B. Electronic leak detector
C. Soap bubble test
D. UV dye
Electronic leak detectors are sensitive to HFC refrigerants and are
widely used in service work.
11. What safety device protects the compressor from high
pressure?
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a refrigeration system?
A. Heating a space
B. Removing heat from a space
C. Producing electricity
D. Filtering air
Refrigeration systems are designed to remove heat from a space
or substance to lower its temperature.
2. Which refrigerant is considered environmentally friendly with low
ozone depletion potential?
A. R-22
B. R-134a
C. R-12
D. R-502
R-134a is a hydrofluorocarbon (HFC) that has zero ozone depletion
potential compared to older CFCs like R-12.
3. What component of a refrigeration system removes heat from the
refrigerant?
A. Compressor
B. Expansion valve
C. Condenser
, D. Evaporator
The condenser releases heat from the refrigerant into the
surrounding environment.
4. In a refrigeration cycle, the refrigerant absorbs heat in the:
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
The evaporator is where the refrigerant absorbs heat from the
space being cooled.
5. Which type of compressor is commonly used in small commercial
refrigeration systems?
A. Screw
B. Centrifugal
C. Reciprocating
D. Axial
Reciprocating compressors are widely used in small and medium
refrigeration systems due to their simplicity and efficiency.
6. What does a thermostatic expansion valve (TXV) control?
A. Compressor speed
B. Condenser fan operation
C. Refrigerant flow to the evaporator
D. System pressure
The TXV regulates the amount of refrigerant entering the
evaporator based on load conditions.
7. What is the function of an accumulator in a refrigeration system?
A. Increase system pressure
, B. Prevent liquid refrigerant from entering the compressor
C. Filter the refrigerant
D. Measure temperature
Accumulators protect compressors by ensuring only vapor enters,
preventing liquid slugging.
8. Which pressure indicates the low side of a refrigeration system?
A. Suction pressure
B. Evaporator pressure
C. Discharge pressure
D. Condenser pressure
Low-side pressure is measured at the evaporator or suction line.
9. What is the purpose of oil in a refrigeration compressor?
A. Cool the evaporator
B. Lubricate moving parts
C. Condense the refrigerant
D. Increase system pressure
Oil reduces friction and wear in the compressor moving parts.
10. Which type of refrigerant leak detector is most commonly
used for HFC refrigerants?
A. Halide torch
B. Electronic leak detector
C. Soap bubble test
D. UV dye
Electronic leak detectors are sensitive to HFC refrigerants and are
widely used in service work.
11. What safety device protects the compressor from high
pressure?
