How does a capacitor store energy?

A capacitor stores energy in the electric field created between its plates. When a voltage is applied across the capacitor's terminals, positive and negative charges accumulate on the respective plates, creating an electric field in the space between them. The energy is stored as electrostatic potential energy in this field, which can be released when the current flows through a circuit as the capacitor discharges.

The design of capacitors allows them to hold this charge and maintain the electric field until the circuit enables a path for the charges to flow back, effectively utilizing the stored energy. This fundamental operation is key to how capacitors function in various applications, such as smoothing out voltage fluctuations and providing bursts of energy in electrical circuits.

Other options mistakenly attribute energy storage to heat generation or magnetic fields. Heat generation describes a resistive process that dissipates energy rather than storing it. Magnetic fields pertain to inductors, which store energy differently by creating a magnetic field when current flows through a coil. The concept of converting energy into direct current does not apply to capacitors since they primarily store energy electrically rather than converting it. Thus, the correct understanding of a capacitor's ability to store energy lies firmly in the creation of an electric field between its plates.