Updated Nevada C-2D Low Voltage Practice Exam 2026
DESCRIPTION
The Nevada C-2D Low Voltage license is an open-book trade certification for
contractors installing systems up to 91 volts, including fiber optics, networking,
audio/video, and security alarms.
Exam Summary
• Trade Exam: 35 questions | 60 minutes | 70% to pass.
• CMS Exam: 60 questions | 120 minutes | 75% to pass (Business & Law).
• Provider: All exams are administered by PSI.
Core Topics
• NEC Standards: Heavy focus on Articles
725 (Control), 770 (Fiber), 800 (Comms), and 250 (Grounding).
• Electrical Theory: Mastery of Ohm’s Law (
) and Watt’s Law (
).
• System Knowledge: Circuitry (Series/Parallel), Voltage Drop calculations,
and Conduit Fill limits.
• Safety: OSHA standards and Class C fire prevention.
Key Licensing Requirements
• Experience: 4 years of verifiable journeyman-level experience.
• Financial: Must provide a financial statement and a Surety Bond.
• Law: Must provide a Notice to Owner regarding liens for residential work.
2026 Question And ANSWER Latest Update
,1. Which NEC Article covers Class 1, Class 2, and Class 3 remote-control,
signaling, and power-limited circuits?
A. Article 800
B. Article 725
C. Article 640
D. Article 770
Rationale: Article 725 is the primary reference for low-voltage control and signaling
circuits.
2. What is the maximum voltage for a Class 2 power-limited circuit?
A. 12 volts
B. 24 volts
C. 30 volts
D. 91 volts
Rationale: Class 2 circuits are typically limited to 30V to prevent electric shock and fire
hazards.
3. According to the NEC, what is the minimum clearance for low-voltage
communication cables crossing over a flat roof?
A. 8 feet
B. 10 feet
C. 12 feet
D. 15 feet
Rationale: To ensure safety and maintenance access, a 8-foot clearance is standard.
4. When installing fiber optic cables, which NEC Article must be followed?
A. Article 725
B. Article 800
C. Article 770
D. Article 300
Rationale: Article 770 specifically governs the installation of optical fiber cables and
raceways.
5. What is the primary purpose of "Grounding" a low-voltage system rack?
A. To increase signal speed
B. To limit the voltage imposed by lightning or line surges
C. To reduce electricity bills
D. To prevent the rack from rusting
2026 Question And ANSWER Latest Update
,Rationale: Grounding provides a path for fault current, protecting equipment and
personnel from surges.
6. Which type of cable is required for use in environmental air-handling spaces
(plenums)?
A. CL2
B. CL2R
C. CL2P
D. CL2X
Rationale: The "P" in CL2P stands for Plenum, indicating the cable has fire-resistant
and low-smoke properties.
7. Ohm’s Law states that Voltage (E) equals:
A. I / R
B. I x R
C. R / I
D. P / I
Rationale: Voltage = Current (Amps) x Resistance (Ohms).
8. If a circuit has a resistance of 10 Ohms and a current of 2 Amps, what is the
Voltage?
A. 5V
B. 12V
C. 20V
D. 100V
Rationale: 10 Ohms x 2 Amps = 20 Volts.
9. In a series circuit, if one bulb burns out, what happens to the other bulbs?
A. They all go out
B. They stay lit
C. They get brighter
D. They flicker
Rationale: In a series circuit, there is only one path for current; a break anywhere
stops all flow.
10. What is the maximum percentage of "Conduit Fill" allowed for a single cable
in a raceway?
A. 31%
B. 53%
C. 40%
D. 60%
2026 Question And ANSWER Latest Update
, Rationale: NEC Table 1 allows 53% fill for 1 wire, 31% for 2 wires, and 40% for 3 or
more.
11. Which color is typically used to identify a "Hot" conductor in a DC circuit?
A. Red
B. Black
C. White
D. Green
Rationale: In DC low-voltage systems, Red is standard for positive/hot and Black for
negative/ground.
12. What is "Voltage Drop"?
A. The amount of electricity used
B. The reduction in voltage as it passes through a conductor's resistance
C. A type of circuit breaker
D. The total power of a battery
Rationale: Voltage drop occurs over long distances or through thin wires, potentially
causing equipment failure.
13. To reduce electromagnetic interference (EMI) in data cabling, you should use:
A. Thicker insulation
B. Solid copper wire
C. Twisted pair cabling (UTP/STP)
D. Aluminum wire
Rationale: Twisting the pairs cancels out magnetic fields and reduces cross-talk.
14. What is the maximum pull tension for standard Category 5e/6 data cable?
A. 10 lbs
B. 25 lbs
C. 50 lbs
D. 100 lbs
Rationale: Pulling harder than 25 lbs can stretch the twists, degrading the cable's
performance.
15. A "Short Circuit" occurs when:
A. Current bypasses the load through a path of little to no resistance
B. The battery is dead
C. The wire is too long
D. The switch is turned off
Rationale: A short creates high current flow, often leading to blown fuses or fires.
2026 Question And ANSWER Latest Update
DESCRIPTION
The Nevada C-2D Low Voltage license is an open-book trade certification for
contractors installing systems up to 91 volts, including fiber optics, networking,
audio/video, and security alarms.
Exam Summary
• Trade Exam: 35 questions | 60 minutes | 70% to pass.
• CMS Exam: 60 questions | 120 minutes | 75% to pass (Business & Law).
• Provider: All exams are administered by PSI.
Core Topics
• NEC Standards: Heavy focus on Articles
725 (Control), 770 (Fiber), 800 (Comms), and 250 (Grounding).
• Electrical Theory: Mastery of Ohm’s Law (
) and Watt’s Law (
).
• System Knowledge: Circuitry (Series/Parallel), Voltage Drop calculations,
and Conduit Fill limits.
• Safety: OSHA standards and Class C fire prevention.
Key Licensing Requirements
• Experience: 4 years of verifiable journeyman-level experience.
• Financial: Must provide a financial statement and a Surety Bond.
• Law: Must provide a Notice to Owner regarding liens for residential work.
2026 Question And ANSWER Latest Update
,1. Which NEC Article covers Class 1, Class 2, and Class 3 remote-control,
signaling, and power-limited circuits?
A. Article 800
B. Article 725
C. Article 640
D. Article 770
Rationale: Article 725 is the primary reference for low-voltage control and signaling
circuits.
2. What is the maximum voltage for a Class 2 power-limited circuit?
A. 12 volts
B. 24 volts
C. 30 volts
D. 91 volts
Rationale: Class 2 circuits are typically limited to 30V to prevent electric shock and fire
hazards.
3. According to the NEC, what is the minimum clearance for low-voltage
communication cables crossing over a flat roof?
A. 8 feet
B. 10 feet
C. 12 feet
D. 15 feet
Rationale: To ensure safety and maintenance access, a 8-foot clearance is standard.
4. When installing fiber optic cables, which NEC Article must be followed?
A. Article 725
B. Article 800
C. Article 770
D. Article 300
Rationale: Article 770 specifically governs the installation of optical fiber cables and
raceways.
5. What is the primary purpose of "Grounding" a low-voltage system rack?
A. To increase signal speed
B. To limit the voltage imposed by lightning or line surges
C. To reduce electricity bills
D. To prevent the rack from rusting
2026 Question And ANSWER Latest Update
,Rationale: Grounding provides a path for fault current, protecting equipment and
personnel from surges.
6. Which type of cable is required for use in environmental air-handling spaces
(plenums)?
A. CL2
B. CL2R
C. CL2P
D. CL2X
Rationale: The "P" in CL2P stands for Plenum, indicating the cable has fire-resistant
and low-smoke properties.
7. Ohm’s Law states that Voltage (E) equals:
A. I / R
B. I x R
C. R / I
D. P / I
Rationale: Voltage = Current (Amps) x Resistance (Ohms).
8. If a circuit has a resistance of 10 Ohms and a current of 2 Amps, what is the
Voltage?
A. 5V
B. 12V
C. 20V
D. 100V
Rationale: 10 Ohms x 2 Amps = 20 Volts.
9. In a series circuit, if one bulb burns out, what happens to the other bulbs?
A. They all go out
B. They stay lit
C. They get brighter
D. They flicker
Rationale: In a series circuit, there is only one path for current; a break anywhere
stops all flow.
10. What is the maximum percentage of "Conduit Fill" allowed for a single cable
in a raceway?
A. 31%
B. 53%
C. 40%
D. 60%
2026 Question And ANSWER Latest Update
, Rationale: NEC Table 1 allows 53% fill for 1 wire, 31% for 2 wires, and 40% for 3 or
more.
11. Which color is typically used to identify a "Hot" conductor in a DC circuit?
A. Red
B. Black
C. White
D. Green
Rationale: In DC low-voltage systems, Red is standard for positive/hot and Black for
negative/ground.
12. What is "Voltage Drop"?
A. The amount of electricity used
B. The reduction in voltage as it passes through a conductor's resistance
C. A type of circuit breaker
D. The total power of a battery
Rationale: Voltage drop occurs over long distances or through thin wires, potentially
causing equipment failure.
13. To reduce electromagnetic interference (EMI) in data cabling, you should use:
A. Thicker insulation
B. Solid copper wire
C. Twisted pair cabling (UTP/STP)
D. Aluminum wire
Rationale: Twisting the pairs cancels out magnetic fields and reduces cross-talk.
14. What is the maximum pull tension for standard Category 5e/6 data cable?
A. 10 lbs
B. 25 lbs
C. 50 lbs
D. 100 lbs
Rationale: Pulling harder than 25 lbs can stretch the twists, degrading the cable's
performance.
15. A "Short Circuit" occurs when:
A. Current bypasses the load through a path of little to no resistance
B. The battery is dead
C. The wire is too long
D. The switch is turned off
Rationale: A short creates high current flow, often leading to blown fuses or fires.
2026 Question And ANSWER Latest Update
