Answer: 56.6 V.
- A 28.3 V
- B 56.6 V
- C 40.0 V
- D 80.0 V
Correct answer: B. 56.6 V
Explanation: The peak emf is E<sub>0</sub> = NBAω = 200×0.4×0.01×100 = 80 V. Hence E<sub>rms</sub> = E<sub>0</sub>/√2 = 56.6 V.
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.