Among the options provided, the Microphone is NOT an actuator.
Here's a brief explanation of each device:
- Microphone: A device that converts sound (acoustic energy) into electrical signals. It is a sensor, not an actuator.
- DC Motor: An actuator that converts electrical energy into mechanical motion.
- Electrical Valve: An actuator that controls the flow of fluid through a pipe or duct based on an electrical signal.
- Speaker: An actuator that converts electrical signals into sound (acoustic energy).
So, the correct answer is Microphone.