What is the role of an actuator?

• A. Measures temperature
• B. Controls feedback
• C. Provides power and motion to manipulate moving parts
• D. Stores energy

Answer: (C)

An actuator’s role is to convert energy into motion to move and manipulate moving parts. In a system, this means taking a control signal and applying power to drive a mechanism—whether it spins a shaft, extends a rod, or adjusts a valve. That’s why it’s described as providing power and motion to manipulate moving parts. Actuators come in various forms: electric motors deliver rotational motion; hydraulic and pneumatic actuators deliver linear motion using fluid pressure. They are the execution devices in a control loop: sensors measure conditions, controllers decide what movement is needed, and actuators carry out that movement. Other functions, like measuring temperature or storing energy, serve sensing or storage roles rather than moving the parts.