What describes an arc in electrical terms?

An arc in electrical terms is best described as a high-temperature luminous electric discharge. This phenomenon occurs when an electrical current jumps across a gap between conductors, creating a plasma that emits light and heat. The high temperature generated during the arc can lead to ignition of surrounding materials, making it a significant concern in fire investigations.

The characteristic of the arc being luminous indicates that it produces visible light due to the high-energy transitions of the excited particles within the plasma. This distinguishes it from other electrical phenomena, as the appearance of light and heat with a significant energy release is a defining feature of an arc.

Understanding this concept is crucial for those involved in fire investigation, as arcs can often be the source of ignition in electrical fires, and identifying their characteristics can assist in determining the cause of a fire.