NEW MEXICO LOW VOLTAGE JOURNEYMAN ES3J
– COMPLETE TESTBANK Verified Q&A | 2026 | NEC
2020 | NFPA 72
1. A low-voltage 48 V DC power-over-Ethernet (PoE) injector supplies
15.4 W per port. What is the maximum current on each port?
A) 0.32 A
B) 0.45 A
C) 0.75 A
D) 1.0 A
Correct Answer: A) 0.32 A
Rationale: Using Ohm's Law (I = P / V), the current is calculated as 15.4 W
divided by 48 V, which equals approximately 0.32 A .
2. What is the OSHA minimum approach distance requirement for
working near 50-volt systems?
A) 1 ft
B) 3 ft
C) 6 ft
D) No minimum distance required
Correct Answer: D) No minimum distance required
Rationale: OSHA does not require a minimum approach distance for voltages
at or below 50 volts, reflecting the lower shock hazard of this voltage class .
,3. Which of the following is the correct wiring method for a PIR
motion sensor requiring a 12 V DC supply?
A) Direct connection to 120 V AC line using a step-down transformer inside
the sensor housing
B) Use a low-voltage power supply and run Class 2 cable to the sensor
C) Connect the sensor to a high-voltage Class 1 circuit with internal
regulation
D) Wire the sensor in parallel with a fire-alarm circuit
Correct Answer: B) Use a low-voltage power supply and run Class 2
cable to the sensor
Rationale: PIR sensors are powered by low-voltage supplies and must use
Class 2 wiring for safety, as Class 2 circuits are power-limited and reduce fire
and shock risk .
4. Which of the following best describes the purpose of a Ufer ground?
A) To provide a dedicated communication pathway
B) To serve as a building's concrete-encased grounding electrode
C) To connect the system to a lightning rod
D) To isolate the system from the main ground
Correct Answer: B) To serve as a building's concrete-encased grounding
electrode
Rationale: A Ufer ground is a concrete-encased grounding electrode typically
using rebar or other metal embedded in the building's concrete foundation. It
provides a low-resistance path to earth .
,5. Which code section mandates the use of firestopping when passing
cables through fire-rated assemblies?
A) NEC Article 300
B) NEC Article 800
C) NEC Article 725
D) NEC Article 760
Correct Answer: A) NEC Article 300
Rationale: NEC Article 300 contains general wiring requirements, including
the use of firestopping to maintain the integrity of fire-rated assemblies when
cables pass through them .
6. What is the typical flash rate for synchronized strobe notification
appliances?
A) 0.5 flashes per second
B) 1 to 2 flashes per second
C) 3 to 4 flashes per second
D) 5 flashes per second
Correct Answer: B) 1 to 2 flashes per second
Rationale: NFPA 72 requires synchronization of visual notification appliances
to flash simultaneously at 1 to 2 flashes per second for effective visual
alerting and compliance .
7. Which device is used to protect low-voltage circuits from voltage
surges and lightning strikes?
, A) Circuit breaker
B) Surge protector
C) Resistor
D) Transformer
Correct Answer: B) Surge protector
Rationale: Surge protectors safeguard sensitive low-voltage circuits by
diverting excess voltage caused by surges and lightning strikes .
8. In the context of low-voltage wiring, what does the term "support
interval" refer to?
A) The time between cable inspections
B) The maximum distance between support points for cables
C) The interval at which devices are tested
D) The duration of circuit activation
Correct Answer: B) The maximum distance between support points for
cables
Rationale: Support interval is the maximum spacing between cable supports,
ensuring cable integrity and preventing sagging or damage .
9. What is the correct minimum conduit size for pulling three 18-AWG
PLTC cables?
A) ½-inch EMT
B) ¾-inch EMT
C) 1-inch EMT
D) ¼-inch
– COMPLETE TESTBANK Verified Q&A | 2026 | NEC
2020 | NFPA 72
1. A low-voltage 48 V DC power-over-Ethernet (PoE) injector supplies
15.4 W per port. What is the maximum current on each port?
A) 0.32 A
B) 0.45 A
C) 0.75 A
D) 1.0 A
Correct Answer: A) 0.32 A
Rationale: Using Ohm's Law (I = P / V), the current is calculated as 15.4 W
divided by 48 V, which equals approximately 0.32 A .
2. What is the OSHA minimum approach distance requirement for
working near 50-volt systems?
A) 1 ft
B) 3 ft
C) 6 ft
D) No minimum distance required
Correct Answer: D) No minimum distance required
Rationale: OSHA does not require a minimum approach distance for voltages
at or below 50 volts, reflecting the lower shock hazard of this voltage class .
,3. Which of the following is the correct wiring method for a PIR
motion sensor requiring a 12 V DC supply?
A) Direct connection to 120 V AC line using a step-down transformer inside
the sensor housing
B) Use a low-voltage power supply and run Class 2 cable to the sensor
C) Connect the sensor to a high-voltage Class 1 circuit with internal
regulation
D) Wire the sensor in parallel with a fire-alarm circuit
Correct Answer: B) Use a low-voltage power supply and run Class 2
cable to the sensor
Rationale: PIR sensors are powered by low-voltage supplies and must use
Class 2 wiring for safety, as Class 2 circuits are power-limited and reduce fire
and shock risk .
4. Which of the following best describes the purpose of a Ufer ground?
A) To provide a dedicated communication pathway
B) To serve as a building's concrete-encased grounding electrode
C) To connect the system to a lightning rod
D) To isolate the system from the main ground
Correct Answer: B) To serve as a building's concrete-encased grounding
electrode
Rationale: A Ufer ground is a concrete-encased grounding electrode typically
using rebar or other metal embedded in the building's concrete foundation. It
provides a low-resistance path to earth .
,5. Which code section mandates the use of firestopping when passing
cables through fire-rated assemblies?
A) NEC Article 300
B) NEC Article 800
C) NEC Article 725
D) NEC Article 760
Correct Answer: A) NEC Article 300
Rationale: NEC Article 300 contains general wiring requirements, including
the use of firestopping to maintain the integrity of fire-rated assemblies when
cables pass through them .
6. What is the typical flash rate for synchronized strobe notification
appliances?
A) 0.5 flashes per second
B) 1 to 2 flashes per second
C) 3 to 4 flashes per second
D) 5 flashes per second
Correct Answer: B) 1 to 2 flashes per second
Rationale: NFPA 72 requires synchronization of visual notification appliances
to flash simultaneously at 1 to 2 flashes per second for effective visual
alerting and compliance .
7. Which device is used to protect low-voltage circuits from voltage
surges and lightning strikes?
, A) Circuit breaker
B) Surge protector
C) Resistor
D) Transformer
Correct Answer: B) Surge protector
Rationale: Surge protectors safeguard sensitive low-voltage circuits by
diverting excess voltage caused by surges and lightning strikes .
8. In the context of low-voltage wiring, what does the term "support
interval" refer to?
A) The time between cable inspections
B) The maximum distance between support points for cables
C) The interval at which devices are tested
D) The duration of circuit activation
Correct Answer: B) The maximum distance between support points for
cables
Rationale: Support interval is the maximum spacing between cable supports,
ensuring cable integrity and preventing sagging or damage .
9. What is the correct minimum conduit size for pulling three 18-AWG
PLTC cables?
A) ½-inch EMT
B) ¾-inch EMT
C) 1-inch EMT
D) ¼-inch
