AC power terminology — is apparent power expressed in watts (W)?

Introduction / Context:Correct AC power units are critical for specifying transformers, UPS systems, and inverters. Apparent power, real power, and reactive power use different units and convey different physical meanings.

Given Data / Assumptions:

• Sinusoidal steady-state conditions.
• Three standard power quantities: real (P), reactive (Q), and apparent (S).

Concept / Approach:Real power P is measured in watts (W). Reactive power Q is measured in volt-ampere reactive (var). Apparent power S is measured in volt-amperes (VA). Apparent power reflects the product of RMS voltage and RMS current irrespective of phase angle.

Step-by-Step Solution:

Verification / Alternative check:Equipment nameplates often list kVA for transformers (apparent power rating) and kW for loads (real power). This practical distinction validates the unit separation.

Why Other Options Are Wrong:

• Choosing “True” conflates apparent power with real power; only P uses watts.

Common Pitfalls:Using kW when sizing generators for loads with poor power factor; the correct initial sizing metric is kVA, then ensure adequate kW capacity given expected PF.

Final Answer:False