Answer: Greater than the source voltage.
- A Greater than the source voltage
- B Equal to the source voltage
- C Less than the source voltage
- D Zero
Correct answer: A. Greater than the source voltage
Explanation: At resonance, VL = I × XL and VC = I × XC can be much larger than the source voltage. This is voltage magnification. The ratio VL/Vsource = Q (quality factor).
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.