Colorado Journeyman Practice Exam 2025 - Free Journeyman Practice Questions and Study Guide

Non-metallic sheathed cable, commonly referred to as NM cable, is widely used in residential electrical systems in Colorado and across the United States. This type of wiring is favored for its flexibility, ease of installation, and relative affordability. NM cable typically consists of two or more insulated conductors along with a bare ground wire, all encased in a plastic sheath, which provides protection and insulation.

The use of NM cable is particularly advantageous for residential applications as it allows for easier routing through walls, ceilings, and various spaces in a home, which is essential during the construction or renovation of residential electrical systems. Furthermore, the National Electrical Code (NEC) permits NM cable for most residential wiring, which adds to its popularity and acceptance in the industry.

In contrast, while metallic conduit has its applications, especially for added protection or in commercial settings, it is not the standard choice for residential wiring. Fiber optic wiring is typically used for data transmission rather than electrical power, making it unsuitable for general residential electrical needs. Twisted pair wiring is also primarily utilized for telecommunications and networking rather than for electrical power distribution in homes. Thus, NM cable stands out as the most appropriate answer for typical residential electrical systems in Colorado.