AR LV Low Voltage Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the maximum voltage typically considered
“low voltage”?
A. 600V
B. 120V
C. 50V
D. 1000V
Rationale: Low voltage in electrical codes is generally defined as
1000 volts or less.
2. Which type of wire is most commonly used for indoor low voltage
applications?
A. THHN
B. Category 5e (Cat5e)
C. Aluminum feeder
D. Rigid conduit
Rationale: Cat5e and Cat6 cables are standard for low voltage indoor
cabling like data and voice.
3. What is the primary purpose of a low voltage transformer?
A. Increase voltage for transmission
B. Step down voltage for devices
C. Protect against overload
D. Measure current flow
Rationale: Low voltage transformers reduce standard line voltage to
safer, usable levels for devices.
,4. Which of the following devices is classified as a low voltage device?
A. Electric water heater
B. Microwave oven
C. Security camera
D. Furnace
Rationale: Security cameras typically operate at 12–24V DC,
classifying them as low voltage.
5. In low voltage systems, the NEC requires grounding for:
A. Every outlet
B. Only high-current circuits
C. Transformers and metallic enclosures
D. None of the above
Rationale: NEC mandates grounding for transformers and metallic
enclosures to prevent shock hazards.
6. What is the typical voltage used for doorbell circuits?
A. 120V AC
B. 220V AC
C. 16–24V AC
D. 5V DC
Rationale: Doorbells generally operate on 16–24V AC from a small
transformer.
7. What is the main standard for telecommunications cabling?
A. NEC Article 250
B. TIA/EIA-568
C. NFPA 70
D. UL 94
Rationale: TIA/EIA-568 sets standards for structured cabling
systems, including low voltage data cabling.
8. Which type of conduit is commonly used for low voltage wiring in
commercial buildings?
A. RMC
B. EMT
C. PVC
D. Aluminum
Rationale: PVC conduit is widely used for low voltage cables due to
its ease of installation and insulation properties.
, 9. What is the purpose of a surge protector in low voltage systems?
A. Increase voltage
B. Convert AC to DC
C. Protect equipment from voltage spikes
D. Provide grounding
Rationale: Surge protectors absorb voltage spikes to prevent damage
to sensitive low voltage equipment.
10. Which of the following is a common voltage for LED lighting
low voltage circuits?
A. 120V AC
B. 12V DC
C. 240V AC
D. 48V AC
Rationale: LED lighting systems often operate at 12V DC supplied by
a low voltage transformer.
11. For network cabling, the maximum run length for Cat5e cable is:
A. 50 meters
B. 75 meters
C. 100 meters
D. 150 meters
Rationale: TIA/EIA standards specify a maximum of 100 meters for
Cat5e horizontal cabling.
12. Which fire alarm component is a low voltage device?
A. Sprinkler head
B. Circuit breaker
C. Smoke detector
D. Fire pump
Rationale: Smoke detectors operate on low voltage circuits, usually
12–24V DC.
13. A low voltage thermostat typically operates at:
A. 120V AC
B. 240V AC
C. 24V AC
D. 48V DC
Rationale: Most residential thermostats use 24V AC for safe
operation of HVAC control circuits.
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the maximum voltage typically considered
“low voltage”?
A. 600V
B. 120V
C. 50V
D. 1000V
Rationale: Low voltage in electrical codes is generally defined as
1000 volts or less.
2. Which type of wire is most commonly used for indoor low voltage
applications?
A. THHN
B. Category 5e (Cat5e)
C. Aluminum feeder
D. Rigid conduit
Rationale: Cat5e and Cat6 cables are standard for low voltage indoor
cabling like data and voice.
3. What is the primary purpose of a low voltage transformer?
A. Increase voltage for transmission
B. Step down voltage for devices
C. Protect against overload
D. Measure current flow
Rationale: Low voltage transformers reduce standard line voltage to
safer, usable levels for devices.
,4. Which of the following devices is classified as a low voltage device?
A. Electric water heater
B. Microwave oven
C. Security camera
D. Furnace
Rationale: Security cameras typically operate at 12–24V DC,
classifying them as low voltage.
5. In low voltage systems, the NEC requires grounding for:
A. Every outlet
B. Only high-current circuits
C. Transformers and metallic enclosures
D. None of the above
Rationale: NEC mandates grounding for transformers and metallic
enclosures to prevent shock hazards.
6. What is the typical voltage used for doorbell circuits?
A. 120V AC
B. 220V AC
C. 16–24V AC
D. 5V DC
Rationale: Doorbells generally operate on 16–24V AC from a small
transformer.
7. What is the main standard for telecommunications cabling?
A. NEC Article 250
B. TIA/EIA-568
C. NFPA 70
D. UL 94
Rationale: TIA/EIA-568 sets standards for structured cabling
systems, including low voltage data cabling.
8. Which type of conduit is commonly used for low voltage wiring in
commercial buildings?
A. RMC
B. EMT
C. PVC
D. Aluminum
Rationale: PVC conduit is widely used for low voltage cables due to
its ease of installation and insulation properties.
, 9. What is the purpose of a surge protector in low voltage systems?
A. Increase voltage
B. Convert AC to DC
C. Protect equipment from voltage spikes
D. Provide grounding
Rationale: Surge protectors absorb voltage spikes to prevent damage
to sensitive low voltage equipment.
10. Which of the following is a common voltage for LED lighting
low voltage circuits?
A. 120V AC
B. 12V DC
C. 240V AC
D. 48V AC
Rationale: LED lighting systems often operate at 12V DC supplied by
a low voltage transformer.
11. For network cabling, the maximum run length for Cat5e cable is:
A. 50 meters
B. 75 meters
C. 100 meters
D. 150 meters
Rationale: TIA/EIA standards specify a maximum of 100 meters for
Cat5e horizontal cabling.
12. Which fire alarm component is a low voltage device?
A. Sprinkler head
B. Circuit breaker
C. Smoke detector
D. Fire pump
Rationale: Smoke detectors operate on low voltage circuits, usually
12–24V DC.
13. A low voltage thermostat typically operates at:
A. 120V AC
B. 240V AC
C. 24V AC
D. 48V DC
Rationale: Most residential thermostats use 24V AC for safe
operation of HVAC control circuits.
