What type of conduit is typically used for outdoor or underground installations?

The correct choice for outdoor or underground installations is rigid metal conduit (RMC). RMC is designed to withstand exposure to the elements and provide robust protection for electrical wiring. Its strong, durable structure makes it ideal for environments where physical impact or moisture may threaten the integrity of the electrical system.

In addition to its durability, RMC also offers excellent grounding capabilities due to its metal composition, which can be beneficial for safety in electrical installations. This conduit type is commonly used in various outdoor applications because it can resist corrosion and other environmental factors more effectively than many alternatives.

While PVC is used for certain outdoor or underground applications due to its corrosion resistance and light weight, it may not provide the same level of physical protection as RMC. EMT, or electrical metallic tubing, is primarily intended for indoor use and offers less protection against physical damage than RMC. Flexible conduit is used in situations requiring bending and movement but lacks the strength needed for underground or outdoor exposure. Therefore, RMC stands out as the most suitable choice for such installations.