Washington Administrative Code(WAC) and Revised Code of Washington (RCW) Electrical Practice Exam

Nonmetallic-sheathed cable, commonly known as NM cable or Romex, is characterized in the Washington Administrative Code (WAC) by its use of nonmetallic insulation, specifically made with polyvinyl chloride (PVC). This type of cable provides electrical conductors that are covered with a flexible plastic sheath, making it suitable for residential wiring applications due to its moisture resistance and overall safety features.

The correct answer highlights that PVC is the insulating material used, which is important for understanding both the cable's application and compliance with safety standards. Nonmetallic sheathing allows for easier handling and installation compared to metal sheathed alternatives while providing necessary insulation to protect against electrical hazards.

The other options do not accurately describe nonmetallic-sheathed cable. Insulation with rubber is not typical for NM cable. The notion of wiring without any insulating material contradicts the very premise of the cable's construction, as insulation is essential for safety. Lastly, wiring made of metal refers to a different category of cables, such as armored cable, which is not applicable to nonmetallic-sheathed cable. Understanding these distinctions helps clarify what nonmetallic-sheathed cable is and why PVC insulation is a key feature in its classification.