NEC Equipment for General Use 3 — Questions and Answers
Question 1: Under NEC 400.12, which use of flexible cord is NOT permitted?
- Connection of portable appliances
- As a substitute for the fixed wiring of a structure (Correct answer)
- Wiring of cranes and hoists
- Connection of stationary equipment to facilitate frequent interchange
Correct answer: As a substitute for the fixed wiring of a structure
NEC 400.12 prohibits flexible cords from being used as a substitute for the fixed wiring of a structure.
Question 2: What is the minimum size fixture wire permitted by NEC 402.6?
- 22 AWG
- 20 AWG
- 18 AWG (Correct answer)
- 16 AWG
Correct answer: 18 AWG
NEC 402.6 states fixture wires shall not be smaller than 18 AWG.
Question 3: A 20-ampere, 125-volt receptacle installed outdoors in a wet location must have what type of enclosure or cover?
- A standard weatherproof flip cover
- A listed, extra-duty in-use (bubble) cover (Correct answer)
- Any cover suitable for damp locations
- A raintight cover only when a GFCI is not provided
Correct answer: A listed, extra-duty in-use (bubble) cover
NEC 406.9(B)(1) requires 15- and 20-ampere receptacles in wet locations to have an enclosure that is weatherproof whether or not a plug is inserted, and it must be listed as extra duty.
Question 4: Per NEC 404.8(A), switches and circuit breakers used as switches must be installed so the center of the operating handle in its highest position is no more than how high above the floor or working platform?
- 6 ft (1.8 m)
- 6 ft 7 in (2.0 m) (Correct answer)
- 7 ft (2.1 m)
- 8 ft (2.5 m)
Correct answer: 6 ft 7 in (2.0 m)
NEC 404.8(A) limits the highest handle position to 2.0 m (6 ft 7 in) above the floor or working platform.
Question 5: In a dwelling unit, which receptacles must be listed tamper-resistant under NEC 406.12?
- Only receptacles below 5 1/2 ft in bedrooms
- Only kitchen countertop receptacles
- All nonlocking 15- and 20-ampere, 125- and 250-volt receptacles in the areas specified (Correct answer)
- Only receptacles within 6 ft of a sink
Correct answer: All nonlocking 15- and 20-ampere, 125- and 250-volt receptacles in the areas specified
NEC 406.12 requires all nonlocking 125-volt and 250-volt, 15- and 20-ampere receptacles in dwelling units to be tamper-resistant, with limited exceptions.
Question 6: What is the minimum thickness required for a ferrous metal receptacle faceplate per NEC 406.6(A)?
- 0.51 mm (0.020 in)
- 0.76 mm (0.030 in) (Correct answer)
- 1.02 mm (0.040 in)
- 1.27 mm (0.050 in)
Correct answer: 0.76 mm (0.030 in)
NEC 406.6(A) requires ferrous metal faceplates to be at least 0.76 mm (0.030 in) thick; nonferrous plates must be 1.02 mm (0.040 in).
Question 7: Under NEC 404.2(C), where must a grounded (neutral) conductor generally be provided at switch locations controlling lighting loads?
- Only in commercial occupancies
- At switch locations where a habitable room or bathroom lighting is controlled, with listed exceptions (Correct answer)
- Only at three-way switch locations
- Only where occupancy sensors are already installed
Correct answer: At switch locations where a habitable room or bathroom lighting is controlled, with listed exceptions
NEC 404.2(C) requires a neutral at most lighting switch locations serving habitable rooms, bathrooms, hallways and similar areas so electronic controls can be installed.
