Answer: 90 degrees (current lags).
- A 0 degrees
- B 45 degrees
- C 90 degrees (current lags)
- D 90 degrees (current leads)
Correct answer: C. 90 degrees (current lags)
Explanation: In a pure inductor, voltage leads current by 90 degrees (or current lags voltage by 90 degrees).
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.