District of Columbia (DC) Journeyman A/C & Refrigeration
(312) Practice Exam Questions with Answers &
Rationales | Instant Pdf Download.
Question 1
In the refrigeration cycle, which component is responsible for compressing the
refrigerant?
A) Condenser
B) Compressor
C) Evaporator
D) Expansion Valve
Correct Answer: B
Explanation: The compressor is the heart of the refrigeration system, taking in low-
pressure, low-temperature refrigerant vapor and compressing it to increase both
pressure and temperature before it moves to the condenser .
Question 2
Which process in the refrigeration cycle involves the refrigerant absorbing heat and
changing from liquid to vapor?
A) Compression
B) Condensation
C) Expansion
D) Evaporation
Correct Answer: D
Explanation: During evaporation, the refrigerant absorbs heat from its surroundings
(the conditioned space) and changes from a liquid to a vapor, producing the cooling
effect .
,Question 3
In a split system air conditioner, which component is typically installed indoors?
A) Outdoor condenser
B) Indoor evaporator coil
C) Compressor
D) Condenser fan
Correct Answer: B
Explanation: In split systems, the evaporator coil is located indoors to cool the interior
air, while the condenser and compressor are placed outdoors .
Question 4
What term describes the difference between the refrigerant's actual temperature and its
saturation temperature at the evaporator outlet?
A) Subcooling
B) Superheat
C) Pressure drop
D) Enthalpy difference
Correct Answer: B
Explanation: Superheat is the extra heat added to the refrigerant vapor beyond its
saturation temperature, measured at the evaporator outlet or compressor suction line.
This ensures that no liquid reaches the compressor .
Question 5
Which component controls the flow of refrigerant into the evaporator and creates a
pressure drop?
A) Compressor
B) Expansion Valve
C) Condenser
D) Receiver
,Correct Answer: B
Explanation: The expansion valve reduces refrigerant pressure before it enters the
evaporator, allowing the refrigerant to expand, cool, and evaporate .
Question 6
The basic principle of refrigeration relies on which law of thermodynamics?
A) First law (conservation of energy)
B) Second law (entropy increase)
C) Third law (absolute zero unattainability)
D) Zeroth law (thermal equilibrium)
Correct Answer: B
Explanation: Refrigeration is based on the second law of thermodynamics, which states
that work is required to move heat from a colder to a warmer place .
Question 7
What is the primary function of the condenser in a refrigeration system?
A) To increase refrigerant pressure
B) To remove heat and condense the refrigerant into a liquid
C) To control superheat
D) To allow refrigerant expansion
Correct Answer: B
Explanation: The condenser rejects heat from the refrigerant to the outside
environment, causing it to condense from a vapor back into a high-pressure liquid .
Question 8
In HVACR, what does "subcooling" refer to?
A) Heating the refrigerant in the compressor
B) Cooling the liquid refrigerant below its saturation temperature
, C) Increasing refrigerant temperature after compression
D) The heat exchange in the evaporator
Correct Answer: B
Explanation: Subcooling occurs after condensation in the condenser, lowering the
liquid refrigerant's temperature below its saturation point without changing pressure .
Question 9
What is the state of refrigerant leaving the compressor?
A) Low-pressure liquid
B) High-pressure superheated vapor
C) Low-pressure vapor
D) High-pressure subcooled liquid
Correct Answer: B
Explanation: The compressor discharges high-temperature, high-pressure superheated
vapor, which then flows to the condenser for heat rejection .
Question 10
What is the state of refrigerant leaving the condenser?
A) Low-pressure vapor
B) High-pressure liquid
C) Low-pressure liquid
D) High-pressure vapor
Correct Answer: B
Explanation: After rejecting heat in the condenser, refrigerant condenses into a high-
pressure liquid before reaching the expansion device .
(312) Practice Exam Questions with Answers &
Rationales | Instant Pdf Download.
Question 1
In the refrigeration cycle, which component is responsible for compressing the
refrigerant?
A) Condenser
B) Compressor
C) Evaporator
D) Expansion Valve
Correct Answer: B
Explanation: The compressor is the heart of the refrigeration system, taking in low-
pressure, low-temperature refrigerant vapor and compressing it to increase both
pressure and temperature before it moves to the condenser .
Question 2
Which process in the refrigeration cycle involves the refrigerant absorbing heat and
changing from liquid to vapor?
A) Compression
B) Condensation
C) Expansion
D) Evaporation
Correct Answer: D
Explanation: During evaporation, the refrigerant absorbs heat from its surroundings
(the conditioned space) and changes from a liquid to a vapor, producing the cooling
effect .
,Question 3
In a split system air conditioner, which component is typically installed indoors?
A) Outdoor condenser
B) Indoor evaporator coil
C) Compressor
D) Condenser fan
Correct Answer: B
Explanation: In split systems, the evaporator coil is located indoors to cool the interior
air, while the condenser and compressor are placed outdoors .
Question 4
What term describes the difference between the refrigerant's actual temperature and its
saturation temperature at the evaporator outlet?
A) Subcooling
B) Superheat
C) Pressure drop
D) Enthalpy difference
Correct Answer: B
Explanation: Superheat is the extra heat added to the refrigerant vapor beyond its
saturation temperature, measured at the evaporator outlet or compressor suction line.
This ensures that no liquid reaches the compressor .
Question 5
Which component controls the flow of refrigerant into the evaporator and creates a
pressure drop?
A) Compressor
B) Expansion Valve
C) Condenser
D) Receiver
,Correct Answer: B
Explanation: The expansion valve reduces refrigerant pressure before it enters the
evaporator, allowing the refrigerant to expand, cool, and evaporate .
Question 6
The basic principle of refrigeration relies on which law of thermodynamics?
A) First law (conservation of energy)
B) Second law (entropy increase)
C) Third law (absolute zero unattainability)
D) Zeroth law (thermal equilibrium)
Correct Answer: B
Explanation: Refrigeration is based on the second law of thermodynamics, which states
that work is required to move heat from a colder to a warmer place .
Question 7
What is the primary function of the condenser in a refrigeration system?
A) To increase refrigerant pressure
B) To remove heat and condense the refrigerant into a liquid
C) To control superheat
D) To allow refrigerant expansion
Correct Answer: B
Explanation: The condenser rejects heat from the refrigerant to the outside
environment, causing it to condense from a vapor back into a high-pressure liquid .
Question 8
In HVACR, what does "subcooling" refer to?
A) Heating the refrigerant in the compressor
B) Cooling the liquid refrigerant below its saturation temperature
, C) Increasing refrigerant temperature after compression
D) The heat exchange in the evaporator
Correct Answer: B
Explanation: Subcooling occurs after condensation in the condenser, lowering the
liquid refrigerant's temperature below its saturation point without changing pressure .
Question 9
What is the state of refrigerant leaving the compressor?
A) Low-pressure liquid
B) High-pressure superheated vapor
C) Low-pressure vapor
D) High-pressure subcooled liquid
Correct Answer: B
Explanation: The compressor discharges high-temperature, high-pressure superheated
vapor, which then flows to the condenser for heat rejection .
Question 10
What is the state of refrigerant leaving the condenser?
A) Low-pressure vapor
B) High-pressure liquid
C) Low-pressure liquid
D) High-pressure vapor
Correct Answer: B
Explanation: After rejecting heat in the condenser, refrigerant condenses into a high-
pressure liquid before reaching the expansion device .
