Electrician National Electrical Code (NEC) 2 — Questions and Answers
Question 1: Per the NEC, what is the minimum headroom clearance required in front of electrical panels?
- 4 feet
- 5 feet
- 6 feet (Correct answer)
- 6.5 feet
Correct answer: 6 feet
NEC 110.26 requires a minimum of 6 feet 6 inches headroom, but 6 feet is the minimum working clearance at the panel face.
Question 2: What is the NEC requirement for the minimum working space depth in front of a 120/240V residential panel?
- 18 inches
- 24 inches
- 30 inches (Correct answer)
- 36 inches
Correct answer: 30 inches
NEC 110.26(A)(1) requires a minimum working space of 3 feet (36 inches) in front of electrical equipment up to 150V to ground.
Question 3: Which NEC article covers swimming pools, fountains, and similar installations?
- Article 410
- Article 500
- Article 680 (Correct answer)
- Article 700
Correct answer: Article 680
NEC Article 680 covers the special electrical requirements for swimming pools, hot tubs, spas, and fountains.
Question 4: According to the NEC, what is the maximum voltage drop allowed for branch circuits serving general lighting and receptacle loads?
- 1%
- 2%
- 3% (Correct answer)
- 5%
Correct answer: 3%
The NEC recommends a maximum of 3% voltage drop for branch circuits to ensure adequate power delivery.
Question 5: Under the NEC, AFCI protection is now required in which residential room?
- Garage
- Bathroom
- Utility room
- Bedroom (Correct answer)
Correct answer: Bedroom
AFCI protection has been required in bedrooms since the 1999 NEC and has since expanded to most living areas.
Question 6: The NEC defines a 'feeder' as all circuit conductors between what two points?
- Service entrance and main panel
- Main panel and branch circuit overcurrent device (Correct answer)
- Branch circuit device and outlet
- Transformer and service entrance
Correct answer: Main panel and branch circuit overcurrent device
A feeder is defined as all circuit conductors between the service equipment or source of power and the final branch-circuit overcurrent device.
Electrician National Electrical Code (NEC) 2
Per the NEC, what is the minimum headroom clearance required in front of electrical panels?