ARRL Technician Practice Exam

Which component is typically used to store electrical energy?

1. Resistor

2. Capacitor

3. Inductor

4. Transformer

The correct answer is: Capacitor

A capacitor is the component typically used to store electrical energy. It accomplishes this by accumulating charge on its plates when connected to a voltage source. The energy is stored in the electric field created between the plates. When needed, this stored energy can be released back into the circuit, which makes capacitors essential in many electronic applications, such as filtering, timing, and energy storage in power supply circuits. Resistors, on the other hand, are designed to resist the flow of electrical current and do not store energy; they convert electrical energy into heat. Inductors store energy in a magnetic field when current flows through them, but this is a different mechanism than what occurs in capacitors. Transformers are used to transfer electrical energy between circuits through electromagnetic induction, but they also do not store energy in the same way that capacitors do.