Metal raceways, cable armor, and other metal enclosures shall be _____ joined together into a continuous electric conductor.

Metal raceways, cable armor, and other metal enclosures must be mechanically joined together to form a continuous electric conductor. This requirement is essential because it ensures that the integrity and continuity of the grounding and bonding system are maintained, which is crucial for the safe operation of electrical systems.

Mechanical connections provide a physical bond between metal components, allowing for the effective conduction of electrical currents and ensuring that there are no interruptions in continuity. This is important not only to facilitate the flow of electricity but also to ensure safety measures are in place. A reliable mechanical connection helps to prevent potential failures due to loosening over time or environmental factors.

In contrast, other terms like electrically, magnetically, or inductively involve methods that do not fulfill the physical bonding needs required for metal raceways and enclosures to act as effective conductors in an electrical system. Thus, the requirement for mechanical joining emphasizes the importance of structural integrity in electrical installations.