Final answer:
A moisture detector is a device that falls into the category of a Sensor, designed to detect and measure the moisture content in various materials or environments. It is not an actuator, which creates mechanical motion, nor a control system, which regulates other devices.
Step-by-step explanation:
A moisture detector is a type of device that is designed to measure the moisture content in various materials or environments. Among the options given, the correct answer is 1) Sensor.
Sensors are devices that detect events or changes in the environment and then provide a corresponding output. In this case, a moisture detector senses the level of humidity or the presence of water in materials like soil, air, wood, and provides a signal that can be read or measured, typically by an electronic device.
On the other hand, an actuator is a device that converts a control signal into mechanical motion. Control usually refers to a system or mechanism that manages the behavior of other devices or systems. Therefore, a sensor like a moisture detector is distinct from actuators and control systems because it functions solely to detect and measure certain variables, not to affect any change or manage other devices.