In what unit is true power expressed?

In what unit is true power expressed?

• A. Watts
• B. VAR
• C. VA
• D. Amperes

Answer: (A)

True power in a circuit is the actual work the load can do, and it is measured in watts. In AC circuits this real power is P = V × I × cosφ, where φ is the phase angle between voltage and current and cosφ is the power factor. The watt value reflects the portion of power that is effectively converted to useful work. Reactive power, measured in VAR (volt-amps reactive), accounts for energy stored and released by inductors and capacitors and does not do net work. Apparent power, measured in VA (volt-amps), is the product of voltage and current without regard to phase angle, representing total power flow. So the unit that expresses true power is watts.

True power in a circuit is the actual work the load can do, and it is measured in watts. In AC circuits this real power is P = V × I × cosφ, where φ is the phase angle between voltage and current and cosφ is the power factor. The watt value reflects the portion of power that is effectively converted to useful work. Reactive power, measured in VAR (volt-amps reactive), accounts for energy stored and released by inductors and capacitors and does not do net work. Apparent power, measured in VA (volt-amps), is the product of voltage and current without regard to phase angle, representing total power flow. So the unit that expresses true power is watts.