Engineering Board Exam Reviewer · RL Circuits · easy
In a purely inductive ac circuit, the current
- leads the voltage by 90°
- is in phase with the voltage
- lags the voltage by 45°
- lags the voltage by 90°
Answer
D. lags the voltage by 90°
Solution
An inductor opposes changes in current, so the current reaches each peak a quarter cycle after the voltage does: the current lags by 90° (ELI: E leads I in an inductor).
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