Which of the following is a key component of a smoke detector?

A smoke detector primarily functions by detecting smoke particles and alerting occupants to the presence of a fire. The key components that enable this functionality are the sensor, power source, and alarm mechanism.

The sensor is crucial as it detects the presence of smoke in the air. This can be an ionization sensor, which reacts quickly to flaming fires, or a photoelectric sensor, which is more responsive to smoldering fires. The power source, typically a battery or hardwired electrical connection, supplies the necessary energy for the detector to operate continuously. Finally, the alarm mechanism is the component that sounds an alarm when smoke is detected, alerting individuals in the vicinity to take action.

While a fire extinguisher and a smoke detector monitoring app are helpful for fire safety, they are not inherent parts of the smoke detector itself. Similarly, a manual reset button can be a feature of some detectors but is not fundamental to the core functionality of detecting smoke. Therefore, the combination of a sensor, power source, and alarm mechanism is what defines a smoke detector's essential components.