Answer: Vrms/Vavg = π/(2√2) ≈ 1.11.
- A Vrms/Vavg = π/(2√2) ≈ 1.11
- B V0/Vrms = √2 as frequently observed in practice
- C Vavg/Vrms in many documented cases
- D Vrms/V0 according to conventional understanding
Correct answer: A. Vrms/Vavg = π/(2√2) ≈ 1.11
Explanation: Form factor = Vrms/Vavg = (V0/√2)/(2V0/π) = π/(2√2) ≈ 1.11. Vavg = 2V0/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.