Exam Questions And Correct Answers

CA C38 Refrigeration Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• What is the primary function of a refrigeration system?
• Heating liquids
• Removing heat from a space
• Increasing pressure in a system
• Storing energy

Answer: B

Rationale: The main purpose of refrigeration is to remove heat from a

designated area or substance, thereby lowering its temperature.

• Which type of refrigerant is considered environmentally safe due to

zero ozone depletion potential (ODP)?

A. R-22

• R-134a

C. R-12

D. R-502

Answer: B

Rationale: R-134a is a hydrofluorocarbon (HFC) with zero ozone

depletion potential, making it safer for the environment compared to CFCs and HCFCs.

• In a vapor-compression refrigeration system, what component is

responsible for compressing the refrigerant vapor?

• Evaporator
• Compressor 1 / 3

• Condenser
• Expansion valve

Answer: B

Rationale: The compressor raises the pressure and temperature of the

refrigerant vapor, enabling it to release heat in the condenser.

• Which of the following is a common refrigerant leak detection method?
• Measuring system pressure only
• Electronic leak detectors
• Visual inspection only
• Listening for compressor noise

Answer: B

Rationale: Electronic leak detectors are widely used to identify small

leaks of refrigerants quickly and accurately.

• What is the typical purpose of a condenser in a refrigeration system?
• Absorb heat
• Reject heat to the surroundings
• Reduce refrigerant pressure
• Convert liquid to vapor

Answer: B

Rationale: The condenser transfers heat from the high-pressure

refrigerant vapor to the external environment, condensing it to a liquid state.

• Which pressure is typically higher in a refrigeration system?
• Suction pressure
• Discharge pressure
• Evaporator pressure
• None of the above

Answer: B

Rationale: Discharge pressure, measured at the compressor outlet, is

higher than suction or evaporator pressures because the compressor raises the refrigerant pressure.

• What is the main hazard of ammonia (R-717) as a refrigerant?
• Low efficiency
• Toxicity and flammability
• Corrosiveness only
• Freezing risk

Answer: B 2 / 3

Rationale: Ammonia is highly efficient but toxic and flammable,

requiring careful handling in refrigeration systems.

• What type of expansion device is commonly used in small refrigeration

systems?

• Capillary tube
• Thermostatic expansion valve (TXV)
• Receiver
• Accumulator

Answer: B

Rationale: A TXV regulates the flow of refrigerant into the evaporator,

maintaining proper superheat and efficient operation.

• What is superheat in a refrigeration system?
• Heat removed in the condenser
• Temperature rise of vapor above its saturation temperature
• Temperature drop in the evaporator
• Heat absorbed during expansion

Answer: B

Rationale: Superheat is the amount by which the temperature of vapor

exceeds its boiling point at a given pressure, ensuring no liquid enters the compressor.

• Which refrigerant is classified as a hydrofluorocarbon (HFC)?

A. R-22

B. R-502

• R-134a

D. R-12

Answer: C

Rationale: HFCs like R-134a contain no chlorine and do not deplete

the ozone layer.

• What is the purpose of a sight glass in a refrigeration system?
• Increase refrigerant pressure
• Allow visual inspection of refrigerant flow and moisture content
• Measure suction temperature
• Serve as an expansion device

Answer: B

Rationale: A sight glass lets technicians verify refrigerant presence

and detect bubbles indicating low charge or moisture.

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