ARRL Technician Practice Exam

Which term describes the rate at which electrical energy is used?

1. Voltage

2. Current

3. Power

4. Resistance

The correct answer is: Power

The term that accurately describes the rate at which electrical energy is used is power. Power is defined as the rate at which work is done or energy is transferred over time. In electrical terms, power can be calculated by multiplying voltage (the potential difference) by current (the flow of electric charge). It is measured in watts, where one watt is equivalent to one joule per second. Voltage refers to the electrical potential difference between two points, which drives the current in a circuit. Current is the flow of electric charge, indicating how many electrons are moving through the conductor. Resistance is a measure of how much a material opposes the flow of electric current. While these terms are related to electrical energy and circuits, none describe the rate of energy use as effectively as power does. Thus, power is the correct answer because it quantifies how much energy is consumed or used over a specific time period.