General HVAC, Electrical & Plumbing Licensing
Exam Practice Questions with Detailed
Rationales latest 2026 Latest version Q&A
|INSTANT DOWNLOAD PDF
1. Which of the following is the primary purpose of a capacitor in an
HVAC system?
A) Reduce voltage
B) Store electrical energy
C) Increase resistance
D) Convert AC to DC
Correct Answer: B – A capacitor stores electrical energy and helps start
motors or maintain voltage in HVAC systems.
2. What type of wiring is commonly used for residential 120/240V
circuits?
A) THHN
B) NM-B (Romex)
C) MC cable
D) BX cable
Correct Answer: B – NM-B (Romex) is widely used in residential wiring
due to its ease of installation and compliance with electrical codes.
3. What is the typical refrigerant used in modern residential air
conditioners?
,A) R-22
B) R-410A
C) R-134a
D) Ammonia
Correct Answer: B – R-410A is commonly used in new residential
systems because R-22 has been phased out due to ozone depletion.
4. In plumbing, which pipe material is most resistant to corrosion?
A) Galvanized steel
B) Copper
C) PEX
D) Cast iron
Correct Answer: C – PEX piping is highly resistant to corrosion and is
flexible, making it suitable for modern plumbing.
5. What does the term “head pressure” in an HVAC system refer to?
A) Pressure in the evaporator
B) Pressure in the condenser
C) Water flow rate
D) Airflow velocity
Correct Answer: B – Head pressure refers to the pressure on the high-
pressure side of a refrigeration system, typically in the condenser.
6. What is the main function of a circuit breaker in an electrical
system?
A) Store energy
B) Limit current flow
,C) Automatically disconnect power during overload
D) Convert voltage
Correct Answer: C – Circuit breakers protect circuits by automatically
disconnecting electricity during overloads or short circuits.
7. Which of the following is a common method for joining copper
pipes?
A) Soldering
B) Threading
C) Compression fittings
D) All of the above
Correct Answer: D – Copper pipes can be joined using soldering,
threading, or compression fittings depending on the application.
8. Which HVAC component is responsible for removing heat from
indoor air?
A) Compressor
B) Evaporator coil
C) Condenser coil
D) Expansion valve
Correct Answer: B – The evaporator coil absorbs heat from indoor air,
cooling it before circulation.
9. What is the minimum clearance required for an electrical panel
according to NEC?
A) 24 inches wide
B) 30 inches high
, C) 36 inches deep
D) 3 feet in front
Correct Answer: D – NEC requires a clear working space of 3 feet in front
of electrical panels for safety and access.
10. Which type of valve is most suitable for throttling water flow in a
plumbing system?
A) Gate valve
B) Globe valve
C) Ball valve
D) Check valve
Correct Answer: B – Globe valves provide precise control for throttling
water flow, unlike gate valves which are fully open or closed.
11. Which refrigerant is classified as a hydrofluorocarbon (HFC)?
A) R-22
B) R-410A
C) Ammonia
D) Carbon dioxide
Correct Answer: B – R-410A is an HFC refrigerant, which does not
deplete the ozone layer like older CFCs or HCFCs.
12. What does “AFUE” stand for in HVAC systems?
A) Annual Fuel Utilization Efficiency
B) Air Flow Unit Efficiency
C) Average Furnace Utility Energy
D) Airflow Factor Under Exhaust
Exam Practice Questions with Detailed
Rationales latest 2026 Latest version Q&A
|INSTANT DOWNLOAD PDF
1. Which of the following is the primary purpose of a capacitor in an
HVAC system?
A) Reduce voltage
B) Store electrical energy
C) Increase resistance
D) Convert AC to DC
Correct Answer: B – A capacitor stores electrical energy and helps start
motors or maintain voltage in HVAC systems.
2. What type of wiring is commonly used for residential 120/240V
circuits?
A) THHN
B) NM-B (Romex)
C) MC cable
D) BX cable
Correct Answer: B – NM-B (Romex) is widely used in residential wiring
due to its ease of installation and compliance with electrical codes.
3. What is the typical refrigerant used in modern residential air
conditioners?
,A) R-22
B) R-410A
C) R-134a
D) Ammonia
Correct Answer: B – R-410A is commonly used in new residential
systems because R-22 has been phased out due to ozone depletion.
4. In plumbing, which pipe material is most resistant to corrosion?
A) Galvanized steel
B) Copper
C) PEX
D) Cast iron
Correct Answer: C – PEX piping is highly resistant to corrosion and is
flexible, making it suitable for modern plumbing.
5. What does the term “head pressure” in an HVAC system refer to?
A) Pressure in the evaporator
B) Pressure in the condenser
C) Water flow rate
D) Airflow velocity
Correct Answer: B – Head pressure refers to the pressure on the high-
pressure side of a refrigeration system, typically in the condenser.
6. What is the main function of a circuit breaker in an electrical
system?
A) Store energy
B) Limit current flow
,C) Automatically disconnect power during overload
D) Convert voltage
Correct Answer: C – Circuit breakers protect circuits by automatically
disconnecting electricity during overloads or short circuits.
7. Which of the following is a common method for joining copper
pipes?
A) Soldering
B) Threading
C) Compression fittings
D) All of the above
Correct Answer: D – Copper pipes can be joined using soldering,
threading, or compression fittings depending on the application.
8. Which HVAC component is responsible for removing heat from
indoor air?
A) Compressor
B) Evaporator coil
C) Condenser coil
D) Expansion valve
Correct Answer: B – The evaporator coil absorbs heat from indoor air,
cooling it before circulation.
9. What is the minimum clearance required for an electrical panel
according to NEC?
A) 24 inches wide
B) 30 inches high
, C) 36 inches deep
D) 3 feet in front
Correct Answer: D – NEC requires a clear working space of 3 feet in front
of electrical panels for safety and access.
10. Which type of valve is most suitable for throttling water flow in a
plumbing system?
A) Gate valve
B) Globe valve
C) Ball valve
D) Check valve
Correct Answer: B – Globe valves provide precise control for throttling
water flow, unlike gate valves which are fully open or closed.
11. Which refrigerant is classified as a hydrofluorocarbon (HFC)?
A) R-22
B) R-410A
C) Ammonia
D) Carbon dioxide
Correct Answer: B – R-410A is an HFC refrigerant, which does not
deplete the ozone layer like older CFCs or HCFCs.
12. What does “AFUE” stand for in HVAC systems?
A) Annual Fuel Utilization Efficiency
B) Air Flow Unit Efficiency
C) Average Furnace Utility Energy
D) Airflow Factor Under Exhaust
