Q99 Refrigeration Machine Operator Newest (2025
- 2026 Update) From Real Past Papers Questions –
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1. What is the primary purpose of a refrigeration system?
A. To increase humidity
B. To remove heat from a space or product
C. To create oxygen
D. To produce electricity
Answer: B. To remove heat from a space or product
The refrigeration cycle transfers heat from a low-temperature area to a higher-
temperature area using a refrigerant.
2. Which major component raises the pressure of refrigerant vapor?
A. Evaporator
B. Expansion valve
C. Compressor
D. Receiver
Answer: C. Compressor
,The compressor compresses low-pressure vapor into high-pressure vapor before it
enters the condenser.
3. What happens to refrigerant inside the condenser?
A. It evaporates
B. It freezes
C. It condenses into a liquid
D. It becomes steam
Answer: C. It condenses into a liquid
The condenser removes heat from the refrigerant, causing it to change from vapor
to liquid.
4. Which component lowers refrigerant pressure before it enters the
evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Oil separator
Answer: C. Expansion valve
The expansion valve reduces pressure and controls refrigerant flow into the
evaporator.
5. What is the purpose of the evaporator?
A. Reject heat
B. Compress refrigerant
C. Absorb heat
D. Store refrigerant
,Answer: C. Absorb heat
The evaporator absorbs heat from the refrigerated space as refrigerant boils.
6. Which state does refrigerant normally enter the compressor?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure vapor
D. Saturated liquid
Answer: B. Low-pressure vapor
Compressors are designed to compress low-pressure vapor, not liquid.
7. Liquid refrigerant entering a compressor can cause:
A. Better efficiency
B. Reduced pressure
C. Liquid slugging
D. Increased airflow
Answer: C. Liquid slugging
Liquid slugging can severely damage compressor valves and pistons.
8. Which instrument measures system pressure?
A. Thermometer
B. Hygrometer
C. Manifold gauge
D. Anemometer
Answer: C. Manifold gauge
The manifold gauge measures both low-side and high-side pressures.
, 9. What color is traditionally used for the low-pressure gauge hose?
A. Red
B. Blue
C. Yellow
D. Green
Answer: B. Blue
The blue hose connects to the low-pressure side of the system.
10.What color is commonly used for the high-pressure hose?
A. Black
B. Green
C. Red
D. White
Answer: C. Red
The red hose connects to the high-pressure side.
11.Which refrigerant condition provides maximum cooling in the evaporator?
A. Superheated vapor
B. High-pressure liquid
C. Boiling refrigerant
D. Compressed liquid
Answer: C. Boiling refrigerant
The refrigerant absorbs significant latent heat while boiling.
12.Superheat refers to:
A. Liquid above boiling point
- 2026 Update) From Real Past Papers Questions –
A Set Of 100 Most Common Exam Frequently
Tested Questions And Answers In Details 100%
Verified Exam Highly Recommendable Grade A+
(Verified Answers) Plus Rationales | Instant
Download Pdf
1. What is the primary purpose of a refrigeration system?
A. To increase humidity
B. To remove heat from a space or product
C. To create oxygen
D. To produce electricity
Answer: B. To remove heat from a space or product
The refrigeration cycle transfers heat from a low-temperature area to a higher-
temperature area using a refrigerant.
2. Which major component raises the pressure of refrigerant vapor?
A. Evaporator
B. Expansion valve
C. Compressor
D. Receiver
Answer: C. Compressor
,The compressor compresses low-pressure vapor into high-pressure vapor before it
enters the condenser.
3. What happens to refrigerant inside the condenser?
A. It evaporates
B. It freezes
C. It condenses into a liquid
D. It becomes steam
Answer: C. It condenses into a liquid
The condenser removes heat from the refrigerant, causing it to change from vapor
to liquid.
4. Which component lowers refrigerant pressure before it enters the
evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Oil separator
Answer: C. Expansion valve
The expansion valve reduces pressure and controls refrigerant flow into the
evaporator.
5. What is the purpose of the evaporator?
A. Reject heat
B. Compress refrigerant
C. Absorb heat
D. Store refrigerant
,Answer: C. Absorb heat
The evaporator absorbs heat from the refrigerated space as refrigerant boils.
6. Which state does refrigerant normally enter the compressor?
A. High-pressure liquid
B. Low-pressure vapor
C. High-pressure vapor
D. Saturated liquid
Answer: B. Low-pressure vapor
Compressors are designed to compress low-pressure vapor, not liquid.
7. Liquid refrigerant entering a compressor can cause:
A. Better efficiency
B. Reduced pressure
C. Liquid slugging
D. Increased airflow
Answer: C. Liquid slugging
Liquid slugging can severely damage compressor valves and pistons.
8. Which instrument measures system pressure?
A. Thermometer
B. Hygrometer
C. Manifold gauge
D. Anemometer
Answer: C. Manifold gauge
The manifold gauge measures both low-side and high-side pressures.
, 9. What color is traditionally used for the low-pressure gauge hose?
A. Red
B. Blue
C. Yellow
D. Green
Answer: B. Blue
The blue hose connects to the low-pressure side of the system.
10.What color is commonly used for the high-pressure hose?
A. Black
B. Green
C. Red
D. White
Answer: C. Red
The red hose connects to the high-pressure side.
11.Which refrigerant condition provides maximum cooling in the evaporator?
A. Superheated vapor
B. High-pressure liquid
C. Boiling refrigerant
D. Compressed liquid
Answer: C. Boiling refrigerant
The refrigerant absorbs significant latent heat while boiling.
12.Superheat refers to:
A. Liquid above boiling point
