CME NEC Code and Theory 2 — Questions and Answers
Question 1: Under NEC Article 210, what is the maximum distance from a doorway that a receptacle outlet must be placed in a dwelling unit wall space?
- 6 feet (Correct answer)
- 12 feet
- 4 feet
- 8 feet
Correct answer: 6 feet
NEC 210.52(A) requires receptacles within 6 feet of any doorway opening in dwelling unit wall spaces.
Question 2: What NEC article covers the installation of transformers and transformer vaults?
- Article 480
- Article 450 (Correct answer)
- Article 460
- Article 490
Correct answer: Article 450
NEC Article 450 covers transformers and transformer vaults, including their installation requirements.
Question 3: According to NEC 230.24, service-entrance conductors above a residential roof must maintain a minimum clearance of how many feet when the roof slope is less than 4 inches in 12?
- 8 feet
- 10 feet
- 3 feet (Correct answer)
- 18 feet
Correct answer: 3 feet
NEC 230.24(A) Exception 2 allows a 3-foot clearance over roofs with a slope less than 4 in 12, provided the service drop doesn't pass more than 4 feet over the roof overhang.
Question 4: NEC 310.15 addresses conductor ampacity. When more than 3 current-carrying conductors are in a raceway, what correction factor applies at exactly 4-6 conductors?
- 0.80 (Correct answer)
- 0.70
- 0.60
- 0.50
Correct answer: 0.80
NEC Table 310.15(C)(1) specifies an 80% (0.80) adjustment factor when 4 to 6 current-carrying conductors are bundled together.
Question 5: Under NEC 404.2(C), a grounded conductor is NOT permitted to serve as the only means of grounding a metal enclosure for a switch. What does this rule require instead?
- A separate equipment grounding conductor must be run to the switch enclosure (Correct answer)
- A ground fault circuit interrupter must be installed
- The switch must be replaced with a GFCI device
- A bonding jumper must connect neutral to the box
Correct answer: A separate equipment grounding conductor must be run to the switch enclosure
NEC 404.2(C) requires a separate equipment grounding conductor to be brought to single-pole switch enclosures, prohibiting sole reliance on the grounded (neutral) conductor.
Question 6: According to NEC 700.12, emergency system sources must be capable of supplying power within how many seconds of normal supply failure?
- 30 seconds
- 10 seconds (Correct answer)
- 60 seconds
- 5 seconds
Correct answer: 10 seconds
NEC 700.12 requires emergency systems to restore power within 10 seconds of loss of normal supply.
Question 7: What is the minimum burial depth for Schedule 80 PVC conduit under a residential driveway per NEC Table 300.5?
- 24 inches
- 18 inches
- 6 inches (Correct answer)
- 12 inches
Correct answer: 6 inches
NEC Table 300.5 allows Schedule 80 PVC conduit to be buried at only 6 inches under driveways at one- and two-family dwellings.
CME NEC Code and Theory 2
Under NEC Article 210, what is the maximum distance from a doorway that a receptacle outlet must be placed in a dwelling unit wall space?