Dictionary Home »
Science » capacitor
capacitor science definition
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.
capacitor
A capacitor is charged when electrons from a power source, such as a battery, flow to one of the two plates. Because the electrons cannot pass through the insulating layer, they build up on the first plate, giving it a negative charge. Electrons on the other plate are attracted to the positive terminal of the battery, causing that plate to become positively charged.
Learn more about capacitor
