Capacitors are classified as which type of electrical component?

• A. Passive electrical component
• B. Active electrical component
• C. Semiconductor device
• D. Electromechanical device

Answer: (A)

Capacitors are passive electrical components because they do not generate or amplify power; they simply store energy and release it as needed. A capacitor has two conductive plates separated by an insulating dielectric. When voltage is applied, charge accumulates on the plates, creating an electric field and storing energy in that field. The current through a capacitor depends on how quickly the voltage across it changes, described by i = C dv/dt. Since it does not require an external power source to operate and cannot supply power to the circuit, it is classified as passive. This sets capacitors apart from active components, which can amplify or switch power and require external energy. They are also not semiconductor devices, which rely on PN junctions, nor electromechanical devices, which involve moving parts. Capacitors serve roles like coupling, decoupling, filtering, and energy storage in countless circuits.