What do capacitors store in an electric circuit?

Capacitors store electrical charge in an electric circuit. They are passive electronic components that can hold a significant amount of electricity and release it when needed. The fundamental principle behind capacitors is that they consist of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied across these plates, an electric field is established, causing positive charge to accumulate on one plate and negative charge on the other.

This storage of charge is what allows capacitors to perform various functions in circuits, such as smoothing out voltage fluctuations, filtering signals in audio applications, and providing temporary power in backup systems. While voltage is related to the charge stored, it is not what the capacitor itself holds; instead, it is the measure of the potential difference that drives the charge into the capacitor. The other options, such as electrical resistance and power supply, refer to different aspects of electrical systems and do not accurately define the role or function of a capacitor.