The role of an actuator in a hydraulic or pneumatic system is to do what?

• A. Store hydraulic fluid
• B. Increase fluid viscosity
• C. Convert fluid power to mechanical energy
• D. Regulate electrical current

Answer: (C)

Actuators convert fluid power into mechanical energy, producing motion and the force needed to do work. When pressurized fluid enters an actuator, it pushes a piston (in a hydraulic or pneumatic cylinder) or drives a rotary element (like a hydraulic motor), turning the energy stored in the fluid into kinetic energy that moves a load. This is what makes the actuator the part of the system that actually performs work, whether you need linear motion to push/ pull or rotary motion to turn a shaft.

Storing hydraulic fluid happens in a reservoir or accumulator, not in the actuator. Increasing fluid viscosity is a property of the fluid itself, not a function of the actuator. Regulating electrical current belongs to electrical or control circuitry, not the actuator's role in converting fluid power to motion.