National Electrical Code (NEC) Article 225 Practice Exam

Non-metallic sheathed cables not rated for outdoor use are prohibited in outdoor installations due to the potential for degradation when exposed to moisture, UV radiation, and temperature fluctuations. Non-metallic sheathed cables that are specifically designed for indoor use may not have the protective characteristics necessary to withstand the environmental stresses encountered outside.

In outdoor settings, it is crucial for electrical installations to use conductors that are rated for such conditions to ensure safety and reliability. Cables intended for outdoor use are usually constructed with materials that offer enhanced resistance to moisture and UV light, ensuring that they will perform effectively and maintain integrity over time.

Other conductors, such as properly rated outdoor cables, insulated conductors designed for outdoor applications, and appropriate low-voltage conductors when specified, can be used in outdoor installations. Therefore, the correct answer highlights the importance of using materials suited for external environments.