How do you calculate electrical power?

How do you calculate electrical power?

• A. P = V × I
• B. P = V / I
• C. P = I / V
• D. P = R × V

Answer: (A)

Power is the rate at which electrical energy is transferred, and in a circuit it comes from multiplying the voltage by the current. So you get Power equals Voltage times Current, with the result in watts. For example, 120 V and 3 A gives 360 W of power. If you know the resistance, you can also use P = I^2R or P = V^2/R, since V = IR ties these forms together. Dividing voltage by current gives resistance, not power, and multiplying resistance by voltage does not produce power in watts, so those alternatives aren’t correct for calculating power.

Power is the rate at which electrical energy is transferred, and in a circuit it comes from multiplying the voltage by the current. So you get Power equals Voltage times Current, with the result in watts. For example, 120 V and 3 A gives 360 W of power. If you know the resistance, you can also use P = I^2R or P = V^2/R, since V = IR ties these forms together. Dividing voltage by current gives resistance, not power, and multiplying resistance by voltage does not produce power in watts, so those alternatives aren’t correct for calculating power.