AR RF Refrigeration Contractor
Exam Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary function of a refrigeration system?
a) Increase air temperature
b) Reduce building pressure
c) Remove heat from a space
d) Remove humidity only
Rationale: Refrigeration systems work by extracting heat from a
conditioned space and rejecting it elsewhere.
2. Which refrigerant classification indicates the lowest flammability?
a) A3
b) B3
c) A1
d) B2
Rationale: A1 refrigerants have low toxicity and no flame propagation.
3. Superheat is measured at which point?
a) Compressor discharge
b) Condenser inlet
c) Evaporator outlet
d) Liquid line
Rationale: Superheat occurs as vapor continues to gain heat after complete
evaporation at the evaporator outlet.
,4. What component separates liquid from vapor refrigerant?
a) Compressor
b) TXV
c) Suction accumulator
d) Receiver
Rationale: Accumulators prevent liquid from entering the compressor by
holding excess liquid.
5. A receiver is typically located on which side of the system?
a) Suction side
b) Low-pressure side
c) High-pressure side
d) Evaporator
Rationale: Receivers store liquid refrigerant after the condenser on the
high-pressure side.
6. The purpose of the TXV is to:
a) Increase compressor capacity
b) Control refrigerant flow into the evaporator
c) Remove moisture from refrigerant
d) Measure system charge
Rationale: TXVs meter refrigerant based on superheat to ensure proper
evaporator operation.
7. Which law explains the relationship between pressure and boiling
point?
a) Ohm’s Law
b) Newton’s Law
c) Charles/Boyle principles
d) Ampere’s Law
Rationale: Gas laws describe how pressure affects temperature and phase
changes.
8. What protects a compressor from overheating?
, a) Sight glass
b) Internal overload
c) Suction accumulator
d) Crankcase heater
Rationale: Thermal overloads open on high temperature to protect
windings.
9. What type of compressor is commonly used in large commercial
systems?
a) Rotary
b) Reciprocating
c) Screw
d) Scroll
Rationale: Screw compressors are efficient for large-tonnage continuous-
duty applications.
10. Low superheat typically indicates:
a) Undercharging
b) Flooding of the evaporator
c) High ambient temperature
d) Compressor overheating
Rationale: Low superheat means there is excess liquid in the evaporator.
11. What is the purpose of subcooling?
a) Warm the suction line
b) Ensure 100% liquid reaches metering device
c) Increase compressor discharge pressure
d) Lower evaporator pressure
Rationale: Subcooling prevents flash gas before the metering device.
12. A filter-drier primarily removes:
a) Air
b) Moisture and contaminants
c) Lubricant
d) Refrigerant
Exam Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary function of a refrigeration system?
a) Increase air temperature
b) Reduce building pressure
c) Remove heat from a space
d) Remove humidity only
Rationale: Refrigeration systems work by extracting heat from a
conditioned space and rejecting it elsewhere.
2. Which refrigerant classification indicates the lowest flammability?
a) A3
b) B3
c) A1
d) B2
Rationale: A1 refrigerants have low toxicity and no flame propagation.
3. Superheat is measured at which point?
a) Compressor discharge
b) Condenser inlet
c) Evaporator outlet
d) Liquid line
Rationale: Superheat occurs as vapor continues to gain heat after complete
evaporation at the evaporator outlet.
,4. What component separates liquid from vapor refrigerant?
a) Compressor
b) TXV
c) Suction accumulator
d) Receiver
Rationale: Accumulators prevent liquid from entering the compressor by
holding excess liquid.
5. A receiver is typically located on which side of the system?
a) Suction side
b) Low-pressure side
c) High-pressure side
d) Evaporator
Rationale: Receivers store liquid refrigerant after the condenser on the
high-pressure side.
6. The purpose of the TXV is to:
a) Increase compressor capacity
b) Control refrigerant flow into the evaporator
c) Remove moisture from refrigerant
d) Measure system charge
Rationale: TXVs meter refrigerant based on superheat to ensure proper
evaporator operation.
7. Which law explains the relationship between pressure and boiling
point?
a) Ohm’s Law
b) Newton’s Law
c) Charles/Boyle principles
d) Ampere’s Law
Rationale: Gas laws describe how pressure affects temperature and phase
changes.
8. What protects a compressor from overheating?
, a) Sight glass
b) Internal overload
c) Suction accumulator
d) Crankcase heater
Rationale: Thermal overloads open on high temperature to protect
windings.
9. What type of compressor is commonly used in large commercial
systems?
a) Rotary
b) Reciprocating
c) Screw
d) Scroll
Rationale: Screw compressors are efficient for large-tonnage continuous-
duty applications.
10. Low superheat typically indicates:
a) Undercharging
b) Flooding of the evaporator
c) High ambient temperature
d) Compressor overheating
Rationale: Low superheat means there is excess liquid in the evaporator.
11. What is the purpose of subcooling?
a) Warm the suction line
b) Ensure 100% liquid reaches metering device
c) Increase compressor discharge pressure
d) Lower evaporator pressure
Rationale: Subcooling prevents flash gas before the metering device.
12. A filter-drier primarily removes:
a) Air
b) Moisture and contaminants
c) Lubricant
d) Refrigerant
