🔍 Key Concepts
• The difference between instantaneous, average, peak, and RMS (root-mean-square) values of an AC sine wave
• How most AC meters are designed and what quantity best represents equivalent heating power compared to DC
• Which quantity is most useful for sizing electrical equipment and conductors
💭 Think About
• For a pure sine wave, which value (peak, peak-to-peak, average, or RMS) best represents the SAME heating effect as a DC voltage?
• When you see a household AC rating like "120 V AC" in North America, is that a peak, average, peak-to-peak, or RMS value?
• If a meter is intended for practical power and safety calculations, which of these four quantities would be the most useful to display directly?
✅ Before You Answer
• Be clear on the definition of RMS voltage and why it matters for power/heat in resistive loads
• Recall what value is marked on utility mains voltage and most AC nameplates (e.g., 120 V, 230 V)
• Eliminate options that represent instantaneous extremes of the waveform rather than its effective working value