Which statement correctly describes the difference between hydraulic and pneumatic cylinders?

• A. Hydraulic uses liquid and offers greater force and precision; Pneumatic uses gas (air) with less force but faster response.
• B. Pneumatic uses liquid and provides more force.
• C. Hydraulic uses gas and is slower to respond.
• D. Pneumatic uses liquid and is more precise.

Answer: (A)

The key idea is how the working medium determines force, speed, and precision. A hydraulic cylinder uses a liquid, which is nearly incompressible. That means applying pressure creates a large, steady force on the piston with very controllable, precise motion. This makes hydraulics ideal for high-force tasks where smooth, accurate positioning is important.

A pneumatic cylinder uses air, a compressible gas. Because it can compress and store energy, the same pressure yields less force for a given piston size, and the force can vary with load and position. The trade-off is quicker, faster movements and simpler systems, but with less precise control.

So the described difference—hydraulic with liquid, offering greater force and precision; pneumatic with gas, providing less force but faster response—fits the reality of how these two types operate.