Answer: 159 Hz.
- A 100 Hz
- B 159 Hz
- C 318 Hz
- D 1000 Hz
Correct answer: B. 159 Hz
Explanation: f = 1/(2π√(LC)) = 1/(2π√(10⁻⁶)) ≈ 159 Hz.
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.