Limited Energy Technician Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the maximum voltage permitted for a Class 2 circuit under
normal conditions?
A. 60 volts
B. 30 volts
C. 50 volts
D. 100 volts
Rationale: Class 2 circuits are limited to 30 volts maximum under
normal operating conditions to reduce shock hazards.
2. Which NEC Article covers Fire Alarm Systems?
A. Article 725
B. Article 760
C. Article 800
, D. Article 820
Rationale: Fire alarm systems are governed by NEC Article 760.
3. What is the primary purpose of a Class 1 circuit?
A. Data transmission
B. Audio communications
C. Remote control and signaling
D. Computer networking
Rationale: Class 1 circuits are designed for remote control and
signaling purposes where higher voltage or power may be required.
4. Which conductor color is typically used for negative polarity in DC
control circuits?
A. White
B. Green
C. Blue
D. Red
Rationale: Blue is commonly used to indicate the negative or grounded
side in DC control wiring.
5. What is the minimum bending radius for a communication cable
according to manufacturer’s instructions?
A. 2 times cable diameter
B. 4 times cable diameter
C. As specified by the manufacturer
D. 10 times cable diameter
, Rationale: The NEC defers to manufacturer instructions for bending
radius limits to prevent cable damage.
6. What type of cable is rated for plenum use?
A. CM
B. CMR
C. CMP
D. CAT6
Rationale: CMP-rated cable is designed for plenum spaces and meets
stringent fire-resistance requirements.
7. Which NEC Article governs communication circuits?
A. 725
B. 760
C. 800
D. 805
Rationale: Article 800 of the NEC covers communication circuits such
as telephone and data wiring.
8. What type of wire insulation is required in a fire-rated cable system?
A. Polyethylene
B. Fire-resistant insulation
C. PVC
D. Nylon
Rationale: Fire-rated systems require insulation materials designed to
resist flame propagation.
, 9. Which color must never be used for an ungrounded conductor?
A. Red
B. Blue
C. Green
D. Black
Rationale: Green is reserved exclusively for grounding conductors.
10. In a low-voltage lighting system, transformers must be listed for
what type of use?
A. Power distribution
B. Low-voltage lighting
C. Industrial control
D. Communication
Rationale: Transformers must be listed specifically for low-voltage
lighting to ensure proper safety compliance.
11. What is the maximum voltage permitted for Class 3 circuits?
A. 24 volts
B. 30 volts
C. 100 volts
D. 150 volts
Rationale: Class 3 circuits can operate up to 100 volts under normal
conditions.
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the maximum voltage permitted for a Class 2 circuit under
normal conditions?
A. 60 volts
B. 30 volts
C. 50 volts
D. 100 volts
Rationale: Class 2 circuits are limited to 30 volts maximum under
normal operating conditions to reduce shock hazards.
2. Which NEC Article covers Fire Alarm Systems?
A. Article 725
B. Article 760
C. Article 800
, D. Article 820
Rationale: Fire alarm systems are governed by NEC Article 760.
3. What is the primary purpose of a Class 1 circuit?
A. Data transmission
B. Audio communications
C. Remote control and signaling
D. Computer networking
Rationale: Class 1 circuits are designed for remote control and
signaling purposes where higher voltage or power may be required.
4. Which conductor color is typically used for negative polarity in DC
control circuits?
A. White
B. Green
C. Blue
D. Red
Rationale: Blue is commonly used to indicate the negative or grounded
side in DC control wiring.
5. What is the minimum bending radius for a communication cable
according to manufacturer’s instructions?
A. 2 times cable diameter
B. 4 times cable diameter
C. As specified by the manufacturer
D. 10 times cable diameter
, Rationale: The NEC defers to manufacturer instructions for bending
radius limits to prevent cable damage.
6. What type of cable is rated for plenum use?
A. CM
B. CMR
C. CMP
D. CAT6
Rationale: CMP-rated cable is designed for plenum spaces and meets
stringent fire-resistance requirements.
7. Which NEC Article governs communication circuits?
A. 725
B. 760
C. 800
D. 805
Rationale: Article 800 of the NEC covers communication circuits such
as telephone and data wiring.
8. What type of wire insulation is required in a fire-rated cable system?
A. Polyethylene
B. Fire-resistant insulation
C. PVC
D. Nylon
Rationale: Fire-rated systems require insulation materials designed to
resist flame propagation.
, 9. Which color must never be used for an ungrounded conductor?
A. Red
B. Blue
C. Green
D. Black
Rationale: Green is reserved exclusively for grounding conductors.
10. In a low-voltage lighting system, transformers must be listed for
what type of use?
A. Power distribution
B. Low-voltage lighting
C. Industrial control
D. Communication
Rationale: Transformers must be listed specifically for low-voltage
lighting to ensure proper safety compliance.
11. What is the maximum voltage permitted for Class 3 circuits?
A. 24 volts
B. 30 volts
C. 100 volts
D. 150 volts
Rationale: Class 3 circuits can operate up to 100 volts under normal
conditions.
