Mechanic (CCQ) Practice Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. What is the primary function of a compressor in a refrigeration
system?
a) Increase the temperature of the refrigerant
b) Increase the pressure of the refrigerant
c) Remove moisture from the refrigerant
d) Filter contaminants from the refrigerant
The compressor increases refrigerant pressure, which raises its
temperature and allows it to release heat in the condenser.
2. Which type of refrigerant is classified as a CFC?
a) R-134a
b) R-12
c) R-410A
d) R-22
CFCs (chlorofluorocarbons) like R-12 are being phased out due to
ozone depletion.
3. In a standard vapor-compression cycle, where does the refrigerant
absorb heat?
a) Compressor
b) Evaporator
c) Condenser
d) Expansion valve
, The evaporator absorbs heat from the surrounding environment,
causing the refrigerant to evaporate.
4. What is the purpose of a condenser in a refrigeration system?
a) Absorb heat from the environment
b) Increase refrigerant velocity
c) Reject heat from the refrigerant
d) Evaporate the refrigerant
The condenser allows high-pressure refrigerant vapor to release
heat and condense into a liquid.
5. Which component controls the flow of refrigerant into the
evaporator?
a) Compressor
b) Receiver
c) Expansion valve
d) Condenser
The expansion valve reduces the pressure of the refrigerant and
regulates its flow into the evaporator.
6. What is the most common cause of compressor failure?
a) Low ambient temperature
b) Lubrication failure
c) High refrigerant velocity
d) Dirty condenser
Lack of lubrication can cause the compressor to overheat and fail.
7. Which pressure is typically lower in a refrigeration system?
a) Condenser pressure
b) Evaporator pressure
c) Suction line pressure
, d) Discharge line pressure
The evaporator operates at a lower pressure to absorb heat
effectively.
8. In a refrigeration system, what is the function of a receiver?
a) Compress the refrigerant
b) Store excess liquid refrigerant
c) Evaporate the refrigerant
d) Increase refrigerant flow
The receiver stores liquid refrigerant from the condenser, ensuring
a steady supply to the expansion valve.
9. Which oil type is commonly used in systems with HFC
refrigerants?
a) Mineral oil
b) POE (Polyol Ester) oil
c) Alkylbenzene oil
d) Silicone oil
POE oils are compatible with HFC refrigerants and provide good
lubrication at high pressures and temperatures.
10. What is the purpose of a sight glass in a refrigeration
system?
a) Measure refrigerant temperature
b) Check refrigerant flow and moisture
c) Increase system pressure
d) Filter refrigerant
A sight glass allows technicians to observe refrigerant flow and
detect moisture or bubbles.