capacitor definition- A device made by placing a dielectric medium (bad conductor) between two metallic conductor plates is called a capacitor. A capacitor is a device that opposes changes in voltage. Mica, ebonite, air etc. are used as dielectric medium (bad conductor) in capacitor. Metals like tin, aluminium etc. are used for conductor plates in … Continue reading what is capacitors? symbol, definition, top most 10 types, useful important facts