Final answer:
Potential energy or voltage introduced into a circuit is called electromotive force (emf). It is the driving force that causes the current through the circuit and is measured in volts (V).
Step-by-step explanation:
Potential energy, or voltage, introduced into a circuit is called a(n) electromotive force (emf). Voltage, which is measured in volts (V), can be thought of as the electrical analog to gravitational potential energy and is the potential difference between two points. In electrical circuits, the voltage or potential difference is what drives the current through the circuit, similar to how pressure moves fluid in a hydraulic system. The terminal voltage (V), is the voltage output of a device measured across its terminals. In terms of electrical energy, when a potential difference is applied to a circuit, it is this potential energy that the charges (such as electrons) possess due to the voltage that can do work as they move through the circuit. A familiar source of voltage is the lead-acid battery, where an energy of 2 electron volts (eV) is typically given to each electron sent to the anode, resulting in a voltage of 2 V.