Which component is primarily responsible for storing electrical energy?

The component primarily responsible for storing electrical energy is a capacitor. Capacitors store electrical energy in an electric field created by the separation of charges on two conductive plates, which are usually separated by an insulating material known as a dielectric. When a voltage is applied across the plates, an electric field is established, and the capacitor accumulates charge. This stored energy can later be released back into the circuit when needed.

In contrast, inductors store energy in a magnetic field when electrical current flows through them. While they do store energy, the primary characteristic of capacitors is their ability to hold and release energy quickly in response to changes in voltage, making them particularly useful in applications like filtering, timing circuits, and energy buffering.

Resistors, on the other hand, do not store energy; they are designed to dissipate it as heat. Their main role in a circuit is to limit current and drop voltage. Transformers are used to transfer electrical energy between circuits through electromagnetic induction, but they do not store electrical energy themselves; rather, they convert energy from one voltage level to another.

In summary, the defining property of a capacitor is its capability to store electrical energy, which is why it is the correct answer in this context.