Extra exam question E5B10
Subelement E5, ELECTRICAL PRINCIPLES· Group E5B
What is the relationship between the AC current through an inductor and the voltage across an inductor?
- A.Voltage leads current by 90 degrees (correct answer)
- B.Current leads voltage by 90 degrees
- C.Voltage and current are 180 degrees out of phase
- D.Voltage and current are in phase
WhyIn an inductor, the AC voltage leads the current by 90 degrees. In an inductor, voltage has to be applied first to drive a changing current through it, so the voltage leads the current by 90 degrees, the standard phase relationship for an ideal inductor, the mirror image of how a capacitor behaves, answer A. Voltage and current aren't in phase or 180 degrees apart in a purely inductive circuit, and it's the voltage that leads, not the current.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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