What protects the wires from the sharp edges of the conduit and is joined to the metal?

• A. Conduit Bushing
• B. Grommet
• C. Ferrule
• D. Strain Relief

Answer: (A)

Conduit bushings are used at the end of metal conduit or in the knockout of a metal box to protect the conductors from the sharp, burr-filled edge of the conduit. They provide a smooth, rounded surface for the wires to pass by and are physically joined to the metal—often threaded into the knockout or fitted into the conduit end—so the interface stays firmly secured and smooth. This combination of edge protection and secure mounting is why this option best fits the description.

Grommets cushion wires as they pass through a hole, but they’re not specifically tied to the conduit edge. Ferrules are used to terminate or reinforce wire ends, not to shield insulation from conduit edges. Strain relief protects against tension on the cable entering a enclosure, rather than protecting the wire from the sharp edge of the conduit.