What does voltage measure in an electric circuit?

Voltage measures the potential difference in an electric circuit, which is the amount of electric potential energy per unit charge between two points in the circuit. It indicates how much work can be done by the electric field on a charge as it moves through the circuit. This potential difference is what drives the flow of electric current; higher voltage means greater potential to push electrons through the circuit.

In the context of an electrical circuit, understanding voltage is crucial because it directly influences how much current will flow when combined with resistance, as described by Ohm's Law. This fundamental relationship is key in the design and analysis of electrical systems.

The other choices pertain to related but distinct concepts in electricity: the rate of charge flow refers to current, the amount of resistance affects the current flow in accordance with Ohm's Law, and energy consumption relates to how much energy is converted into other forms (like heat or light) in a circuit. Each concept is important in its own right, but none directly define what voltage measures.