What is the standard unit used to express electrical power?

What is the standard unit used to express electrical power?

• A. Volt
• B. Ohm
• C. Watt
• D. Ampere

Answer: (C)

Power is the rate at which electrical energy is used or transferred. The standard unit for that rate is the watt. A watt equals one volt times one ampere (P = V × I). So you determine how much power a device uses by multiplying the voltage by the current it draws. The volt measures electrical potential, the ohm measures resistance, and the ampere measures current. In residential alarm work, device specifications are typically given in watts, and you size circuits and power supplies based on total wattage or by converting current at the system voltage (P = V × I).

Power is the rate at which electrical energy is used or transferred. The standard unit for that rate is the watt. A watt equals one volt times one ampere (P = V × I). So you determine how much power a device uses by multiplying the voltage by the current it draws. The volt measures electrical potential, the ohm measures resistance, and the ampere measures current. In residential alarm work, device specifications are typically given in watts, and you size circuits and power supplies based on total wattage or by converting current at the system voltage (P = V × I).