Answer: 0.
- A 0
- B I<sub>0</sub>/2
- C 2I<sub>0</sub>/π
- D I<sub>0</sub>
Correct answer: A. 0
Explanation: The positive and negative half cycles have equal magnitude and opposite sign, so their contributions cancel over one complete cycle. The average current is therefore zero.
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.