Automotive EOP Practice Test

The driving potential provided by the power source is the voltage that pushes electrons around the circuit. This is the source voltage—the electrical pressure the source can supply to move charges. The actual voltage you see across the external circuit (the terminal voltage) can be lower than this when the source has internal resistance, while the voltage across the load is simply the portion of the circuit’s voltage dropped across the load itself. Electromotive force is the traditional term for the energy per unit charge the source provides, and it’s closely related to the idea of source voltage. In this context, the term that best matches “the amount of voltage available to move electrons through a circuit” is the source voltage, since it describes the driving potential the source can deliver.