Answer: V rms /V avg = π/(2√2) ≈ 1.11.
- A V<sub>rms</sub>/V<sub>avg</sub> = π/(2√2) ≈ 1.11
- B V<sub>0</sub>/V<sub>rms</sub> = √2 as frequently observed in practice
- C V<sub>avg</sub>/V<sub>rms</sub> in many documented cases
- D V<sub>rms</sub>/V<sub>0</sub> according to conventional understanding
Correct answer: A. V<sub>rms</sub>/V<sub>avg</sub> = π/(2√2) ≈ 1.11
Explanation: Form factor = V<sub>rms</sub>/V<sub>avg</sub> = (V<sub>0</sub>/√2)/(2V<sub>0</sub>/π) = π/(2√2) ≈ 1.11. V<sub>avg</sub> = 2V<sub>0</sub>/π for a full-wave rectified sine.
In a pure inductor the current lags the voltage by 90° (energy is briefly stored in the magnetic field before current responds); in a pure capacitor the current leads the voltage by 90° (current must flow to build up charge before voltage rises) - the mnemonic "ELI the ICE man" keeps these straight.
Concept context
AC circuits, impedance, LCR series circuit, resonance, transformers, and power factor.