Which component is primarily used to reduce noise in an electrical circuit?

The component primarily used to reduce noise in an electrical circuit is a capacitor. Capacitors can effectively filter out high-frequency noise signals while allowing low-frequency signals to pass through. This filtering action is crucial in preventing unwanted noise from affecting the performance of sensitive electronic components. Additionally, capacitors are often employed in power supply circuits to smooth out voltage spikes and dips, further contributing to a cleaner signal.

In contrast, inductors are generally used to store energy in a magnetic field and can filter signals based on frequency; however, they are less effective at noise reduction in the context of electrical circuits. Resistors, while they can limit current, do not actively reduce noise and can actually contribute to power loss. Transformers are mainly used for voltage conversion and isolation rather than noise reduction.