Which electrical mechanism is commonly associated with ignition due to arcing between conductors?

• A. Arcing
• B. Resistance
• C. Overcurrent
• D. Sparking

Answer: (A)

Arcing is the electrical mechanism at play. When conductors have a gap and a high enough voltage, the air between them becomes ionized and a continuous discharge, or arc, forms a plasma channel. This arc concentrates a lot of energy in a small area, reaching extreme temperatures and emitting intense heat and radiant energy that can ignite flammable vapors, liquids, or dust nearby. That combination of heat, light, and molten debris is what makes arcing a common ignition source in electrical systems. Resistance heating refers to heat generated inside conductors themselves, not an arc between conductors; overcurrent is a condition that can trip protective devices and isn’t the ignition mechanism by itself, and sparking is a brief discharge that can occur at contacts but the sustained discharge between conductors is the ignition-relevant mechanism.