Maryland HVACR Master Restricted
Exam Practice Questions And Correct
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Rationale 2026 Q&A| Instant Download
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1. Which component is primarily responsible for raising the pressure and
temperature of refrigerant vapor in a vapor-compression refrigeration
system?
A. Expansion valve
B. Evaporator
C. Condenser
D. Compressor
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature
vapor before it enters the condenser.
2. What is the primary purpose of superheating refrigerant vapor leaving
the evaporator?
A. Increase condenser pressure
B. Ensure no liquid refrigerant enters the compressor
C. Reduce airflow requirements
D. Increase latent heat
,Rationale: Superheat confirms that all refrigerant has vaporized before
reaching the compressor, preventing damaging liquid slugging.
3. Which psychrometric property represents the actual amount of
moisture in the air?
A. Relative humidity
B. Dew point
C. Humidity ratio
D. Dry-bulb temperature
Rationale: Humidity ratio measures the mass of water vapor per unit mass
of dry air and directly indicates moisture content.
4. A clogged air filter most commonly causes which condition?
A. Increased airflow
B. Reduced static pressure
C. Reduced airflow across the evaporator coil
D. Increased ventilation rate
Rationale: A dirty filter restricts airflow, reducing air movement through
the HVAC system and potentially causing performance issues.
5. Which electrical device provides overload protection for a motor?
A. Relay
B. Transformer
C. Capacitor
D. Overload protector
Rationale: Overload protectors interrupt power when excessive current or
temperature threatens motor damage.
6. What is the function of a condenser in a refrigeration system?
, A. Add heat to refrigerant
B. Lower pressure of refrigerant
C. Reject heat from refrigerant to a cooling medium
D. Meter refrigerant flow
Rationale: The condenser transfers heat from refrigerant to air or water,
causing refrigerant vapor to condense into liquid.
7. Which instrument is commonly used to measure air velocity in ducts?
A. Micrometer
B. Manometer
C. Thermocouple
D. Anemometer
Rationale: An anemometer measures air speed and is frequently used in
HVAC airflow testing.
8. What is the boiling point of a refrigerant dependent upon?
A. Voltage
B. Amperage
C. Pressure
D. Airflow
Rationale: Refrigerants boil and condense at temperatures directly related
to system pressure.
9. Which type of heat is associated with a temperature change?
A. Latent heat
B. Sensible heat
C. Fusion heat
D. Vaporization heat
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. Which component is primarily responsible for raising the pressure and
temperature of refrigerant vapor in a vapor-compression refrigeration
system?
A. Expansion valve
B. Evaporator
C. Condenser
D. Compressor
Rationale: The compressor draws low-pressure refrigerant vapor from the
evaporator and compresses it into a high-pressure, high-temperature
vapor before it enters the condenser.
2. What is the primary purpose of superheating refrigerant vapor leaving
the evaporator?
A. Increase condenser pressure
B. Ensure no liquid refrigerant enters the compressor
C. Reduce airflow requirements
D. Increase latent heat
,Rationale: Superheat confirms that all refrigerant has vaporized before
reaching the compressor, preventing damaging liquid slugging.
3. Which psychrometric property represents the actual amount of
moisture in the air?
A. Relative humidity
B. Dew point
C. Humidity ratio
D. Dry-bulb temperature
Rationale: Humidity ratio measures the mass of water vapor per unit mass
of dry air and directly indicates moisture content.
4. A clogged air filter most commonly causes which condition?
A. Increased airflow
B. Reduced static pressure
C. Reduced airflow across the evaporator coil
D. Increased ventilation rate
Rationale: A dirty filter restricts airflow, reducing air movement through
the HVAC system and potentially causing performance issues.
5. Which electrical device provides overload protection for a motor?
A. Relay
B. Transformer
C. Capacitor
D. Overload protector
Rationale: Overload protectors interrupt power when excessive current or
temperature threatens motor damage.
6. What is the function of a condenser in a refrigeration system?
, A. Add heat to refrigerant
B. Lower pressure of refrigerant
C. Reject heat from refrigerant to a cooling medium
D. Meter refrigerant flow
Rationale: The condenser transfers heat from refrigerant to air or water,
causing refrigerant vapor to condense into liquid.
7. Which instrument is commonly used to measure air velocity in ducts?
A. Micrometer
B. Manometer
C. Thermocouple
D. Anemometer
Rationale: An anemometer measures air speed and is frequently used in
HVAC airflow testing.
8. What is the boiling point of a refrigerant dependent upon?
A. Voltage
B. Amperage
C. Pressure
D. Airflow
Rationale: Refrigerants boil and condense at temperatures directly related
to system pressure.
9. Which type of heat is associated with a temperature change?
A. Latent heat
B. Sensible heat
C. Fusion heat
D. Vaporization heat
