capacitor [%PREMIUM_LINK%] (kə-pās'ĭ-tər) Pronunciation Key |
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An electrical device consisting of two conducting plates separated by an electrical insulator (the dielectric), designed to hold an electric charge. Charge builds up when a voltage is applied across the plates, creating an electric field between them. current can flow through a capacitor only as the voltage across it is changing, not when it is constant. Capacitors are used in power supplies, amplifiers, signal processors, oscillators, and logic gates. Compare induction coil, resistor.