In a hydraulic circuit, which component provides linear motion to perform work?

• A. Cylinder
• B. Pump
• C. Reservoir
• D. Valve

Answer: (A)

In hydraulics, the device that turns fluid pressure into straight-line motion is the hydraulic cylinder, an actuator. Inside a cylinder, a piston slides along the bore as pressurized fluid enters, pushing the piston and extending or retracting the rod. That linear movement is what does the actual work, lifting, pressing, or pushing a load. The force produced comes from pressure acting on the piston area (Force = Pressure × Area), and the motion’s speed and direction are controlled by valves and the flow from the pump. The pump provides the energy, the reservoir stores fluid, and the valve directs flow, but the cylinder is the component that delivers linear motion to perform work.