What term describes the phenomenon where an electric arc spreads further apart until it breaks?

The correct term for the phenomenon where an electric arc spreads further apart until it breaks is known as arcing horns. Arcing horns are designed components that help manage and control electrical arcs, particularly in electrical equipment such as circuit breakers or power lines. When voltage levels are too high, or when disconnection occurs, the electric arc can extend, causing an increase in distance between the conductors. Arcing horns provide a controlled pathway for the arc to travel along, which helps to protect equipment from damage and maintain safety.

Understanding the role of arcing horns is crucial in electrical engineering and safety practices, as they play a significant part in managing the stability of electrical connections during transient conditions. This term highlights the design considerations for preventing uncontrolled arcing and the subsequent destruction it can cause in various electrical systems.