When a voltage is applied to a circuit and current flows through the load, what is consumed?

When voltage is applied to a circuit and current flows through a load, the measure that represents the rate at which energy is consumed is power. Power is defined as the rate at which work is done or the rate at which energy is transferred or converted. In electrical terms, it is calculated using the formula Power = Voltage x Current. This means that as current flows through a load due to the applied voltage, energy is used up in the form of electrical power.

Understanding power is critical in electrical engineering because it relates directly to how much energy is being consumed by devices. For example, when a light bulb or any load is connected to a voltage source, it draws current according to its resistance, resulting in a specific power consumption that can be measured in watts.

In contrast, while energy is consumed in the circuit, it is the power that quantifies how quickly or at what rate this energy is being consumed. Voltage, on the other hand, is simply the potential difference that drives the current through the circuit, and resistance is the property of the load that impedes current flow, but neither of them directly describes the consumption rate.