Ham Radio General Class Practice Test

What principle does a capacitor operate on?

1. Inductive reactance

2. Electrical resistance

3. Farads

4. Storing electrical charge

The correct answer is: Storing electrical charge

A capacitor operates on the principle of storing electrical charge. When a voltage is applied across its terminals, it allows electric charge to accumulate on its plates, creating an electric field. This capacity to store energy in the form of an electric charge is fundamental to the function of capacitors, making them essential components in various electrical and electronic circuits. The other options do not accurately describe the primary function of a capacitor. Inductive reactance relates to how inductors behave in AC circuits, while electrical resistance pertains to how components impede the flow of current. The term "Farads" refers to the unit of capacitance that measures a capacitor's ability to store charge, but it doesn't describe the principle itself. Therefore, the defining characteristic of a capacitor is indeed its ability to store electrical charge.