A device used to store an electrical charge.

A device used to store an electrical charge.

• A. Battery
• B. Ammeter
• C. Ampere
• D. Capacitor

Answer: (D)

Capacitance stores energy in the electric field between two conductors separated by a dielectric. When a voltage is applied, charges accumulate on the plates, creating a stored charge Q = C·V and energy W = ½ C V^2. This allows rapid charging and discharging, which is why capacitors are used for smoothing, filtering, timing, and transient energy storage in circuits. A battery stores energy chemically, not as a field between plates, so its charging/discharging behavior differs. An ammeter simply measures current, and ampere is the unit of current, not a storage device. So the device that stores an electrical charge is a capacitor.

Capacitance stores energy in the electric field between two conductors separated by a dielectric. When a voltage is applied, charges accumulate on the plates, creating a stored charge Q = C·V and energy W = ½ C V^2. This allows rapid charging and discharging, which is why capacitors are used for smoothing, filtering, timing, and transient energy storage in circuits. A battery stores energy chemically, not as a field between plates, so its charging/discharging behavior differs. An ammeter simply measures current, and ampere is the unit of current, not a storage device. So the device that stores an electrical charge is a capacitor.