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ASVAB · Components and Devices

What is the basic function of a capacitor?

Reviewed by Jordan Morley, Editorial Lead at 247SimpleTests. Written by the 247SimpleTests Editorial Team from the official source material cited on every question.

Correct answer

To store electrical energy in an electric field

  1. A To produce light
  2. B To store electrical energy in an electric field
  3. C To block all current permanently
  4. D To convert current to voltage

Why this is the answer

A capacitor stores electrical energy in an electric field between two conductive plates separated by an insulator (dielectric). It can charge up and then release that energy, which makes capacitors useful for smoothing out voltage, filtering signals, and providing short bursts of power. Capacitance is measured in farads. Unlike a battery, a capacitor stores energy electrostatically and can charge and discharge very quickly. Knowing that a capacitor stores charge — distinct from a resistor (limits current) or inductor (stores energy in a magnetic field) — is standard component knowledge.
Source: ASVAB Electronics Information — Capacitors

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About this topic: Components and Devices

Components and devices questions cover what resistors, capacitors, inductors, diodes, transistors, transformers, fuses and switches do, and their schematic symbols. Recognising a symbol and naming its job is most of the section. This is one of 19 Electronics Information questions on components and devices, each with a full explanation on a single study page.

New to this exam? Our ASVAB exam guide explains the format, scoring, and how to prepare.

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