What is a common ignition source associated with resistance heating?

The selection of overloaded wiring as the common ignition source associated with resistance heating is grounded in the fundamental principles of electrical systems. Resistance heating occurs when electricity passes through a conductor that resists the flow of current, generating heat as a result. When wiring is overloaded, it means that the electrical current exceeds the safe capacity of the wires. This excess current leads to an increase in thermal energy due to resistance, which can cause the wires to heat up significantly.

Overheated wires can reach temperatures that exceed the ignition point of surrounding materials, leading to the potential for fire. As the insulation around the wires deteriorates from the heat, it further exacerbates the danger by exposing conductive materials, or by causing additional resistance and heating. This phenomenon makes overloaded wiring a prevalent risk factor in fire incidents related to electrical systems.

Other options like incorrect wiring, gaps in insulation, and external heat sources can contribute to fire risks but are not as directly related to the specific mechanism of resistance heating as overloaded wiring. Incorrect wiring does not always result in immediate heat generation unless compounded by other factors, while gaps in insulation primarily allow for heat loss rather than accumulation. External heat sources might ignite materials, but they are not related specifically to the principles of resistance heating within electrical systems.