Which of the following is a potential heat source?

Electrical energy is considered a potential heat source because it can generate heat when it flows through resistance in wires, appliances, or any conductive materials. This principle is often utilized in electric heaters, ovens, and other appliances designed specifically to produce heat. When electricity encounters resistance, it transforms into thermal energy, which can be harnessed for various applications, including cooking, heating spaces, or powering machinery.

Propane is primarily a fuel source that, when burned, produces heat through combustion, making it a heat-producing substance but not a direct form of energy by itself. Hydrogen, similar to propane, can be used as a fuel to generate heat when it reacts with oxygen, but again, it does not serve as a heat source in the same way electrical energy does. Carbon monoxide is a byproduct of incomplete combustion and is hazardous, but it does not generate heat directly; rather, it can indicate the presence of a more dangerous heat-generating reaction that has gone wrong.