What is power?

What is power?

• A. The rate at which work is done
• B. The current through a circuit
• C. The energy stored in a system
• D. The resistance of a circuit

Answer: (A)

Power is the rate at which energy is transferred or work is done. It tells you how quickly energy is used or moved. For example, if a device does 60 joules of work every second, its power is 60 joules per second, or 60 watts. In electrical circuits, power can be written as P = V × I, the product of voltage and current, which is exactly the rate of energy transfer. The other ideas describe different quantities: current is the flow of electric charge; energy stored is the total energy contained in a system (not how fast it’s used); resistance is how much a component resists current, affecting power but not being power itself.

Power is the rate at which energy is transferred or work is done. It tells you how quickly energy is used or moved. For example, if a device does 60 joules of work every second, its power is 60 joules per second, or 60 watts. In electrical circuits, power can be written as P = V × I, the product of voltage and current, which is exactly the rate of energy transfer. The other ideas describe different quantities: current is the flow of electric charge; energy stored is the total energy contained in a system (not how fast it’s used); resistance is how much a component resists current, affecting power but not being power itself.