In an inductor
Correct answer: A. Emf leads the current by 90°
- A. Emf leads the current by 90°
- B. Current leads the voltage by 90°
- C. Both are in phase
- D. None
Explanation
In a purely inductive AC circuit, the voltage (or EMF) across the inductor is maximum when the rate of change of current is maximum. This results in the voltage waveform leading the current waveform by a phase angle of 90°.
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About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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