Final answer:
A protective plate must be used if a wire is closer than 1.25 inches to the surface of a stud to prevent damage by screws or nails during construction work.
Step-by-step explanation:
A protective plate is required if a wire is less than 1.25 inches from the surface of the stud. This requirement helps to protect wires from damage by screws or nails during the construction or renovation process. When installing electrical wiring in buildings, strict adherence to building codes is crucial for safety.