Maryland HVACR Master License Exam Newest
(2025 - 2026 Update) From Real Past Papers
Questions – Set 100 Most Common Exam
Frequently Tested Questions And Answers In
Details 100% Verified Exam Highly
Recommendable For Grade A+
1. Which instrument is primarily used to measure refrigerant system suction
and discharge pressures?
A. Clamp ammeter
B. Digital manifold gauge set
C. Hygrometer
D. Anemometer
Answer: B. Digital manifold gauge set
Explanation: A manifold gauge set is specifically designed to measure both low-
side and high-side refrigerant pressures for system diagnosis.
2. Superheat is defined as:
A. The temperature below the saturation point
B. The temperature above the refrigerant's saturation temperature
C. Condensing temperature
D. Evaporator pressure
Answer: B. The temperature above the refrigerant's saturation temperature
,Explanation: Superheat indicates that the refrigerant has completely vaporized
and has absorbed additional sensible heat.
3. A thermostatic expansion valve primarily controls:
A. Compressor speed
B. Condenser airflow
C. Refrigerant flow into the evaporator
D. Liquid line pressure
Answer: C. Refrigerant flow into the evaporator
Explanation: The TXV meters refrigerant according to evaporator load by
maintaining proper superheat.
4. Which component removes moisture from the refrigerant?
A. Receiver
B. Accumulator
C. Filter-drier
D. Oil separator
Answer: C. Filter-drier
Explanation: Filter-driers remove moisture, acids, and contaminants from the
refrigerant circuit.
5. A compressor that repeatedly starts and stops within short intervals is said
to be:
A. Flooding
B. Cycling normally
C. Short cycling
D. Equalizing
,Answer: C. Short cycling
Explanation: Short cycling reduces efficiency and can damage compressor
components.
6. Which refrigerant line should always be insulated?
A. Liquid line
B. Suction line
C. Hot gas bypass line
D. Receiver outlet
Answer: B. Suction line
Explanation: Insulating the suction line minimizes heat gain and prevents
condensation.
7. Low airflow across an evaporator coil commonly causes:
A. Higher suction pressure
B. Lower superheat
C. Evaporator icing
D. Higher condenser pressure
Answer: C. Evaporator icing
Explanation: Reduced airflow lowers coil temperature, allowing moisture to
freeze.
8. Which electrical law states that voltage equals current multiplied by
resistance?
A. Boyle's Law
B. Charles' Law
C. Ohm's Law
, D. Kirchhoff's Law
Answer: C. Ohm's Law
Explanation: Ohm's Law is V = I × R.
9. A capacitor is tested using:
A. Megohmmeter only
B. Capacitance meter
C. Thermometer
D. Refrigerant scale
Answer: B. Capacitance meter
Explanation: A capacitance meter measures the actual microfarad value.
10.Which motor generally requires both a start and run capacitor?
A. PSC motor
B. Shaded pole motor
C. Capacitor-start capacitor-run motor
D. Universal motor
Answer: C. Capacitor-start capacitor-run motor
Explanation: These motors use separate capacitors for starting and running
performance.
11.Refrigerant leaving the condenser should normally be:
A. Saturated vapor
B. Superheated vapor
C. Subcooled liquid
D. Flash gas
(2025 - 2026 Update) From Real Past Papers
Questions – Set 100 Most Common Exam
Frequently Tested Questions And Answers In
Details 100% Verified Exam Highly
Recommendable For Grade A+
1. Which instrument is primarily used to measure refrigerant system suction
and discharge pressures?
A. Clamp ammeter
B. Digital manifold gauge set
C. Hygrometer
D. Anemometer
Answer: B. Digital manifold gauge set
Explanation: A manifold gauge set is specifically designed to measure both low-
side and high-side refrigerant pressures for system diagnosis.
2. Superheat is defined as:
A. The temperature below the saturation point
B. The temperature above the refrigerant's saturation temperature
C. Condensing temperature
D. Evaporator pressure
Answer: B. The temperature above the refrigerant's saturation temperature
,Explanation: Superheat indicates that the refrigerant has completely vaporized
and has absorbed additional sensible heat.
3. A thermostatic expansion valve primarily controls:
A. Compressor speed
B. Condenser airflow
C. Refrigerant flow into the evaporator
D. Liquid line pressure
Answer: C. Refrigerant flow into the evaporator
Explanation: The TXV meters refrigerant according to evaporator load by
maintaining proper superheat.
4. Which component removes moisture from the refrigerant?
A. Receiver
B. Accumulator
C. Filter-drier
D. Oil separator
Answer: C. Filter-drier
Explanation: Filter-driers remove moisture, acids, and contaminants from the
refrigerant circuit.
5. A compressor that repeatedly starts and stops within short intervals is said
to be:
A. Flooding
B. Cycling normally
C. Short cycling
D. Equalizing
,Answer: C. Short cycling
Explanation: Short cycling reduces efficiency and can damage compressor
components.
6. Which refrigerant line should always be insulated?
A. Liquid line
B. Suction line
C. Hot gas bypass line
D. Receiver outlet
Answer: B. Suction line
Explanation: Insulating the suction line minimizes heat gain and prevents
condensation.
7. Low airflow across an evaporator coil commonly causes:
A. Higher suction pressure
B. Lower superheat
C. Evaporator icing
D. Higher condenser pressure
Answer: C. Evaporator icing
Explanation: Reduced airflow lowers coil temperature, allowing moisture to
freeze.
8. Which electrical law states that voltage equals current multiplied by
resistance?
A. Boyle's Law
B. Charles' Law
C. Ohm's Law
, D. Kirchhoff's Law
Answer: C. Ohm's Law
Explanation: Ohm's Law is V = I × R.
9. A capacitor is tested using:
A. Megohmmeter only
B. Capacitance meter
C. Thermometer
D. Refrigerant scale
Answer: B. Capacitance meter
Explanation: A capacitance meter measures the actual microfarad value.
10.Which motor generally requires both a start and run capacitor?
A. PSC motor
B. Shaded pole motor
C. Capacitor-start capacitor-run motor
D. Universal motor
Answer: C. Capacitor-start capacitor-run motor
Explanation: These motors use separate capacitors for starting and running
performance.
11.Refrigerant leaving the condenser should normally be:
A. Saturated vapor
B. Superheated vapor
C. Subcooled liquid
D. Flash gas
