What does a ‘live line’ refer to in electrical terminology?

A 'live line' refers specifically to a wire that carries an electrical current. In electrical terminology, this means that the conductor is energized and has voltage present, making it capable of delivering power to devices or circuits that are connected to it. Understanding this concept is crucial for safety and proper handling of electrical installations, as live lines pose a risk of electric shock or short circuits if not managed correctly.

The other options describe conditions that do not align with the definition of a ‘live line.’ For instance, a wire that is disconnected from any source does not carry current and is therefore not live. Similarly, a conductor that carries no voltage can be considered inactive and cannot be referred to as a live line. Lastly, while insulation is important for safety, a wire that is primarily insulated doesn't inherently indicate that it carries current; it merely prevents accidental contact with live wiring. Thus, the understanding that a live line is one that actively carries electrical current is essential in the field of electrical installations.