🔍 Key Concepts
• In AC circuits, voltage × current gives a type of power, but there are different kinds: real (true), reactive, and apparent power
• A voltmeter measures RMS (root mean square) voltage and an ammeter measures RMS current in AC systems
• Think about single‑phase AC power where basic textbooks define S, P, and Q (apparent, real, and reactive power)
💭 Think About
• When you multiply the RMS voltage reading by the RMS current reading, are you automatically including the effect of power factor (cos φ), or not?
• Which term is used for the simple product V × I in an AC circuit, before adjusting for phase angle between voltage and current?
• Which kind of power (real, reactive, or apparent) is actually delivered as usable work to a load, and which one is just the combination of them on a power triangle?
✅ Before You Answer
• Confirm which power uses the formula P = V × I × power factor (cos φ)
• Confirm which power is represented by the symbol S and measured in volt‑amperes (VA), not watts
• Eliminate any choice that is not a standard electrical engineering term for AC power.