Which of the following is not a basic component of a switch or receptacle?

• A. Terminal screw
• B. Insulating body
• C. Faceplate
• D. Lock spring

Answer: (D)

A switch or receptacle is built around things that enable it to connect wires, isolate safely, and be mounted and covered. The terminal screws are where the wires attach, the insulating body keeps electricity from escaping and protects you, and the faceplate provides a finished cover and access to the terminals. A lock spring isn’t a standard part you’d find in a basic switch or receptacle; it’s not needed for the normal operation of lighting or outlet control. Some locking mechanisms exist in specialized equipment, but for everyday devices, this component isn’t considered a basic part.