Answer: 1.4 A.
- A 1.4 A
- B 2.8 A
- C 0.7 A
- D 44 A
Correct answer: A. 1.4 A
Explanation: X<sub>L</sub> = 2π × 50 × 0.5 = 157 Ω. I<sub>rms</sub> = V<sub>rms</sub>/X<sub>L</sub> = 220/157 ≈ 1.4 A.
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.