What does a wiring diagram show?

A wiring diagram is a detailed illustration that displays the connections and actual locations of all components within a specific electrical system or equipment. This type of diagram is essential for understanding how different parts of the system interact and where they are situated, which can aid in troubleshooting, installation, and maintenance. By clearly representing the physical layout and wiring of components, such as switches, outlets, and circuits, a wiring diagram allows technicians and electricians to efficiently plan and execute electrical work.

In contrast, the other options do not accurately represent the purpose of a wiring diagram. While electrical principles of operation are important for understanding how systems function, these principles are not depicted in a wiring diagram. Similarly, only noting supply voltage and current ratings does not capture the comprehensive view that a wiring diagram provides, which includes both connection details and component locations. Therefore, the selection indicating the connection and actual location of all components underscores the primary function of a wiring diagram in the electrical field.