Answer: V 0 /√2.
- A V<sub>0</sub>/√2
- B V<sub>0</sub>/2
- C V<sub>0</sub>√2
- D 2V<sub>0</sub>
Correct answer: A. V<sub>0</sub>/√2
Explanation: V<sub>rms</sub> = V<sub>0</sub>/√2 ≈ 0.707 V<sub>0</sub>. For household current (230 V RMS), the peak voltage is 230 × √2 ≈ 325 V.
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.