A capacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary battery. Capacitors are commonly used in electronic devices to maintain power supply while batteries are being changed.
Conventional electrostatic capacitors provide less than 360 joules per kilogram of energy density, while capacitors using developing technology can provide more than 2.52 kilojoules per kilogram.
In car audio systems, large capacitors store energy for the amplifier to use on demand.
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1.they are used to reduce voltage fluctuations in power supplies and to increase the efficiency of power transmission.
2.they are used to generate electromagnetic oscillations and in tuning the radio circuits.
3. they are usd in the ignition system of automobiles engines to eliminate sparking
4. now a days super capacitors are used to more energy from low input