Nate Electrical Practice Exam

What's one key function of a capacitor in an electrical system?

1. To amplify signals

2. To store and release electric charge

3. To convert AC to DC

4. To provide thermal insulation

The correct answer is: To store and release electric charge

A capacitor plays a significant role in electrical systems primarily by storing and releasing electric charge. This ability to store energy in an electric field allows capacitors to stabilize voltage and power flow in various applications. When a voltage is applied across its terminals, the capacitor charges up to that voltage, and when the circuit requires it, the capacitor can discharge, providing energy back into the circuit. This function is crucial in smoothing out fluctuations in electrical signals, filtering noise, and providing temporary power during brief interruptions. In power supply applications, capacitors help maintain a constant voltage level, ensuring that devices operate reliably. The other functions listed, such as amplifying signals or converting AC to DC, are performed by other components. For instance, transistors handle signal amplification, and rectifiers are responsible for converting alternating current (AC) into direct current (DC). Thermal insulation is entirely unrelated to capacitors, as it pertains to maintaining temperature rather than managing electric charge.