What best describes voltage in an electrical circuit?

Voltage is best described as the pressure or push within a circuit. This concept is fundamental in electrical theory, where voltage represents the potential difference between two points in an electrical circuit. It is the driving force that moves electric charges through a conductor, similar to how water pressure pushes water through pipes.

Understanding voltage as a "push" helps clarify its role in the flow of current. Without this electrical pressure, there would be no movement of electrons, and hence no current flow. This is essential for the operation of electrical devices, as they rely on voltage to function properly.

The other descriptions relate to different aspects of electrical circuits. For instance, resistance refers to the opposition to the flow of current, and while it affects how much current flows given a certain voltage, it does not describe what voltage itself is. The measurement of electrical power, typically calculated as the product of voltage and current, defines the rate at which electrical energy is consumed, not the voltage itself. Finally, the capacity of a battery relates to how much energy it can store, which is influenced by voltage but does not define it. Thus, voltage is accurately described as the pressure or push within a circuit.