Answer: It becomes four times the original value.
- A It becomes twice the original value
- B It becomes three times the original value
- C It becomes four times the original value
- D It becomes eight times the original value
Correct answer: C. It becomes four times the original value
Explanation: The generated peak emf E<sub>0</sub> = NBAω, so doubling ω doubles the emf. Halving the load resistance doubles the current again. Therefore the RMS current becomes four times its original value.
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.