Internet of Things (IoT) Practice Exam

Which of the following components is typically classified as an actuator?

1. Thermometer

2. Microcontroller

3. Relay

4. Sensor

The correct answer is: Relay

The classification of an actuator includes devices that perform actions or movements in response to signals or inputs. A relay, as highlighted in the correct answer, is a type of actuator because it controls the flow of electricity in a circuit, functioning as a switch that can turn devices on or off. When it receives a signal from a control system, it physically closes or opens the circuit to activate or deactivate electrical devices, making it integral in automated systems. In contrast, a thermometer is classified as a sensor since it measures temperature but does not perform any physical actions. A microcontroller serves as a brain for controlling processes and integrating inputs from various devices but does not exert mechanical force or movement on its own. Lastly, a sensor detects environmental conditions or changes but, like the thermometer, does not physically perform actions in response to stimuli. Thus, the relay is uniquely characterized as an actuator among these options because of its role in executing actions based on received signals.