EXAM Questions And Correct Answer with
Rational (100% verified answer) Q & A 2026
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1. What is the primary function of an HVAC system?
A. Generate electricity
B. Control temperature, humidity, and air quality
C. Produce refrigerant
D. Increase air pressure
Answer: B
Rationale: HVAC systems regulate heating, ventilation, and air conditioning for
comfort and air quality.
2. Which refrigerant was commonly used before environmental restrictions?
A. R-410A
B. R-134a
C. R-22
D. R-32
Answer: C
Rationale: R-22 (Freon) was widely used but phased out due to ozone depletion.
3. What does BTU stand for?
A. British Thermal Unit
B. Basic Thermal Utility
C. Built Temperature Unit
,D. Balanced Thermal Unit
Answer: A
Rationale: BTU measures heat energy.
4. Which component removes heat from refrigerant?
A. Compressor
B. Evaporator
C. Condenser
D. Expansion valve
Answer: C
Rationale: The condenser releases heat absorbed by the refrigerant.
5. The evaporator coil is located where?
A. Outside unit
B. Inside air handler
C. Compressor housing
D. Refrigerant tank
Answer: B
Rationale: The evaporator absorbs heat inside the indoor unit.
6. What is the function of the compressor?
A. Cools air
B. Circulates refrigerant
C. Compresses refrigerant gas
D. Expands liquid refrigerant
Answer: C
Rationale: The compressor raises refrigerant pressure and temperature.
, 7. Which gas law explains pressure-temperature relationship in HVAC?
A. Boyle’s Law
B. Ohm’s Law
C. Pascal’s Law
D. Newton’s Law
Answer: A
Rationale: Boyle’s Law relates pressure and volume of gases.
8. What tool measures refrigerant pressure?
A. Thermometer
B. Manifold gauge
C. Anemometer
D. Psychrometer
Answer: B
Rationale: Manifold gauges measure system pressures.
9. What is superheat?
A. Liquid refrigerant temperature
B. Gas above saturation temperature
C. Compressor overheating
D. Heat loss in condenser
Answer: B
Rationale: Superheat is vapor heated above boiling point.
10. What is subcooling?
A. Cooling below freezing
B. Liquid cooled below condensing temperature
C. Gas compression stage