Which NEC article defines key terms like branch circuit, feeder, and service?

• A. Article 90
• B. Article 100
• C. Article 250
• D. Article 310

Answer: (B)

The main idea is that exact meanings for terms used throughout the NEC are set in a dedicated Definitions article. This article defines branch circuit, feeder, and service, so you know precisely what parts of a wiring system each term refers to. That clarity is essential because it tells you which rules apply to each portion of the system and what equipment is involved. The other articles cover different aspects—general scope and requirements, grounding and bonding, or conductor sizing—but they don’t define these fundamental terms. So the Definitions article is the source you turn to for what those terms mean.