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AC theoryQuestion 957 of 1506

In a pure capacitive AC circuit, which statement about voltage and current is correct?

  1. Current leads voltage by 90 degrees
  2. Voltage leads current by 90 degrees
  3. Voltage and current are in phase
  4. Current lags voltage by 45 degrees
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Correct answer: Current leads voltage by 90 degrees

Capacitor current follows the rate of change of voltage, so the current wave is ahead of the voltage wave.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 4.2: AC Capacitor Circuits

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Questions last reviewed: 18 October 2026