ASVAB (Armed Services Vocational Aptitude Battery)Electronics Information (EI)Easy

Which of the following is the primary function of an inductor in an AC circuit?

  1. ATo block DC current
  2. BTo store electrical charge
  3. CTo convert AC to DC
  4. DTo oppose changes in current
Show answer & explanation

Correct answer: D. To oppose changes in current

An inductor's primary function is to oppose changes in the current flowing through it, which it does by generating a back electromotive force (EMF). This property is due to its magnetic field.

Why the other options are wrong

  • A. Inductors pass DC current with only the resistance of their wire, but they do not block it; capacitors block DC.
  • B. This is the function of a capacitor.
  • C. This is the function of a rectifier circuit, often using diodes.

Inductor Function

An inductor is a passive electrical component that stores energy in a magnetic field when electric current flows through it, and its primary function is to oppose changes in current.

  • Opposes changes in current flow.
  • Stores energy in a magnetic field.
  • Measured in Henries (H).

Memory trick: Inductors Insist on Inertia of Current.

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