DC JOURNEYMAN A/C & REFRIGERATION EXAM COMPLETE QUESTIONS AND CORRECT ANSWERS LATEST VERSION PASS GUARANTEE

1. What is the primary function of the compressor in a refrigeration
system?
A. Absorb heat from the conditioned space
B. Increase refrigerant pressure and temperature
C. Condense refrigerant vapor into liquid
D. Meter refrigerant into the evaporator
ANSWER : B
Explanation: The compressor raises the pressure and temperature of refrigerant
vapor so it can release heat in the condenser.


2. Which refrigerant property allows heat absorption in the evaporator?
A. High pressure
B. Latent heat of vaporization
C. High density
D. Chemical stability
ANSWER : B
Explanation: Refrigerants absorb large amounts of heat during phase change
from liquid to vapor due to latent heat.


3. Which component removes moisture and contaminants from the
refrigerant?
A. Evaporator
B. Condenser
C. Filter-drier
D. Expansion valve
ANSWER : C
Explanation: Filter-driers remove moisture, acids, and debris that could
damage the system.

,4. What device controls refrigerant flow into the evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
ANSWER : C
Explanation: Expansion devices regulate refrigerant flow and reduce pressure
before the evaporator.


5. Superheat is measured at the:
A. Condenser outlet
B. Compressor discharge
C. Evaporator outlet
D. Liquid line
ANSWER : C
Explanation: Superheat is measured at the evaporator outlet to ensure vapor-
only refrigerant enters the compressor.


6. Excessive superheat indicates:
A. Overcharged system
B. Restricted airflow
C. Underfeeding evaporator
D. Flooded evaporator
ANSWER : C
Explanation: High superheat means insufficient refrigerant entering the
evaporator.


7. Which law states that pressure and temperature are directly related?
A. Boyle’s Law
B. Charles’ Law
C. Dalton’s Law
D. Ohm’s Law

, ANSWER : B
Explanation: Charles’ Law states that temperature increases cause pressure
increases when volume is constant.


8. What happens when condenser airflow is restricted?
A. Lower head pressure
B. Higher head pressure
C. Lower suction pressure
D. Reduced superheat
ANSWER : B
Explanation: Restricted airflow prevents heat rejection, increasing condenser
pressure.


9. Which refrigerant is classified as an HFC?
A. R-22
B. R-12
C. R-410A
D. R-717
ANSWER : C
Explanation: R-410A is an HFC refrigerant with zero ozone depletion
potential.


10. EPA Section 608 certification is required to:
A. Install ductwork
B. Handle refrigerants
C. Wire HVAC controls
D. Test combustion gases
ANSWER : B
Explanation: EPA 608 certification is mandatory for handling regulated
refrigerants.


11. Which tool is used to measure air velocity?

, A. Manometer
B. Anemometer
C. Hygrometer
D. Psychrometer
ANSWER : B
Explanation: An anemometer measures airflow velocity.


12. A low suction pressure may indicate:
A. Overcharge
B. Dirty evaporator coil
C. Restricted condenser
D. Excess refrigerant
ANSWER : B
Explanation: Dirty evaporator coils restrict heat absorption, lowering suction
pressure.


13. What safety device opens when system pressure becomes excessive?
A. Thermostat
B. Solenoid valve
C. Pressure relief valve
D. Expansion valve
ANSWER : C
Explanation: Pressure relief valves prevent system rupture from excessive
pressure.


14. What is the normal state of refrigerant leaving the condenser?
A. Vapor
B. Liquid
C. Superheated vapor
D. Saturated vapor
ANSWER : B
Explanation: Refrigerant exits the condenser as a high-pressure liquid.