What is the Sparkover effect of a voltage surge?

• A. A disruptive discharge along a solid material such as an insulator string or a live-line-tool
• B. A disruptive discharge through the air
• C. A disruptive discharge along a solid material such as rubber covering, rubber gloves, or a fiber conductor cover
• D. None of the above

Answer: (B)

Sparkover is the sudden arcing path that forms when a surge is strong enough to ionize the air between conductors, allowing current to jump through the air as a discharge. This happens when the electric field across an air gap exceeds its breakdown strength, so the arc travels through the air rather than along the surface of insulation. Among the options, the description of a disruptive discharge through the air best fits this phenomenon. The other descriptions refer to discharges that travel along solid insulating surfaces or coverings, which are surface or creepage/tracking actions rather than sparkover through air.