Which unit best describes electric power in a circuit?

Electric power in a circuit is measured in watts. This unit quantifies the rate at which electrical energy is transferred or converted in a circuit over time. One watt is defined as one joule of energy per second. In practical terms, when discussing electrical systems, watts are the most relevant measure, as they directly relate to the ability of a circuit to perform work or provide energy to devices.

The relationship among power, voltage, and current is given by the formula: Power (P) = Voltage (V) × Current (I). This equation illustrates that power is dependent on both the voltage applied across a circuit and the current flowing through it, reinforcing the significance of watts as the unit of power measurement.

Ohms measure resistance, which is a different aspect of electrical circuits. Volts measure electrical potential, indicating how much potential energy exists to drive the current, but does not describe how much energy is being used or consumed. Joules measure energy rather than power; while related, they denote the total amount of energy rather than the rate at which energy is used or produced in a circuit.