Electrical arcing occurs when?

Electrical arcing occurs when high voltage electricity jumps between two conductors. This phenomenon is typically seen when there is insufficient insulation or separation between conductive materials, allowing the electrical current to overcome the air gap and create a visible spark or arc. Arcing can lead to significant heat production and damage, and it can pose serious safety risks, making it important to understand in the context of electrical systems.

The other options do not correctly describe conditions under which arcing would occur. A battery losing its acid would impact its functionality but is not directly related to the phenomenon of arcing itself. A heating element glowing red hot indicates it is operating normally under resistance but does not involve a jump of electricity between two separate conductive materials. Lastly, while a resistor expanding upon heating relates to thermal effects in electrical components, it does not involve the electrical discharge characteristic of arcing.