NM cable is not suitable for which locations unless rated and protected?

• A. Wet locations or exposed outdoor use
• B. Dry indoor walls
• C. Concrete walls
• D. Crawl spaces with no protection

Answer: (A)

NM cable is designed for dry indoor locations only. Its insulation is not rated to withstand moisture or exposure to the elements, so in wet locations or when used outdoors without protection it can deteriorate and create shock or fire hazards. That’s why it must be rated for wet/damp locations and installed with appropriate protection (such as weatherproof enclosures or conduit) if you’re wiring in those areas. In contrast, dry indoor walls are exactly where NM is intended to be used, and other scenarios like crawl spaces or concrete walls require different methods or additional protection to meet code.