Texas HVAC Technician Exam Verified Questions, Correct
Answers, and Detailed Explanations for Science
Students||Already Graded A+
1. What is the primary purpose of a contactor?
A. Regulate voltage
B. Store electricity
C. Control high-voltage equipment with low-voltage signals
D. Reduce amperage
Contactors allow thermostats to safely control compressors and
motors.
2. Which refrigerant has the highest ozone depletion potential?
A. R-410A
B. R-134a
C. R-22
D. R-32
R-22 is an HCFC and contributes to ozone depletion.
3. Superheat is measured at the:
A. Condenser outlet
B. Liquid line
C. Evaporator outlet (suction line)
D. Compressor discharge
Superheat indicates how much vapor heating occurs after
evaporation.
4. Which device meters refrigerant into the evaporator?
,A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
Metering devices control refrigerant flow and pressure drop.
5. A capacitor’s function is to:
A. Increase resistance
B. Store refrigerant
C. Provide starting and running torque for motors
D. Lower voltage
Capacitors improve motor efficiency and starting power.
6. Low suction pressure may indicate:
A. Overcharge
B. Dirty condenser
C. Restricted airflow or low refrigerant
D. High load
Reduced heat load lowers evaporator pressure.
7. Which electrical law states V = I × R?
A. Kirchhoff’s Law
B. Ohm’s Law
C. Faraday’s Law
D. Watt’s Law
Ohm’s Law defines the relationship between voltage, current, and
resistance.
8. The evaporator’s main function is to:
, A. Reject heat outdoors
B. Compress vapor
C. Absorb heat from indoor air
D. Store refrigerant
Heat absorption cools the indoor space.
9. Which tool measures airflow?
A. Multimeter
B. Manifold gauge
C. Anemometer
D. Megohmmeter
Anemometers measure air velocity.
10. A dirty condenser coil will cause:
A. Low head pressure
B. High head pressure
C. Low superheat
D. Low amperage
Restricted heat rejection raises condensing pressure.
11. Which component protects against overcurrent?
A. Relay
B. Transformer
C. Circuit breaker
D. Thermostat
Breakers open the circuit when current exceeds limits.
12. Subcooling is measured at the:
Answers, and Detailed Explanations for Science
Students||Already Graded A+
1. What is the primary purpose of a contactor?
A. Regulate voltage
B. Store electricity
C. Control high-voltage equipment with low-voltage signals
D. Reduce amperage
Contactors allow thermostats to safely control compressors and
motors.
2. Which refrigerant has the highest ozone depletion potential?
A. R-410A
B. R-134a
C. R-22
D. R-32
R-22 is an HCFC and contributes to ozone depletion.
3. Superheat is measured at the:
A. Condenser outlet
B. Liquid line
C. Evaporator outlet (suction line)
D. Compressor discharge
Superheat indicates how much vapor heating occurs after
evaporation.
4. Which device meters refrigerant into the evaporator?
,A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
Metering devices control refrigerant flow and pressure drop.
5. A capacitor’s function is to:
A. Increase resistance
B. Store refrigerant
C. Provide starting and running torque for motors
D. Lower voltage
Capacitors improve motor efficiency and starting power.
6. Low suction pressure may indicate:
A. Overcharge
B. Dirty condenser
C. Restricted airflow or low refrigerant
D. High load
Reduced heat load lowers evaporator pressure.
7. Which electrical law states V = I × R?
A. Kirchhoff’s Law
B. Ohm’s Law
C. Faraday’s Law
D. Watt’s Law
Ohm’s Law defines the relationship between voltage, current, and
resistance.
8. The evaporator’s main function is to:
, A. Reject heat outdoors
B. Compress vapor
C. Absorb heat from indoor air
D. Store refrigerant
Heat absorption cools the indoor space.
9. Which tool measures airflow?
A. Multimeter
B. Manifold gauge
C. Anemometer
D. Megohmmeter
Anemometers measure air velocity.
10. A dirty condenser coil will cause:
A. Low head pressure
B. High head pressure
C. Low superheat
D. Low amperage
Restricted heat rejection raises condensing pressure.
11. Which component protects against overcurrent?
A. Relay
B. Transformer
C. Circuit breaker
D. Thermostat
Breakers open the circuit when current exceeds limits.
12. Subcooling is measured at the:
