Pneumatic describes operation by what?

• A. Compressed air.
• B. Electrical power.
• C. Hydraulic fluid.
• D. Manual mechanical action.

Answer: (D)

Pneumatic describes operation by compressed air. In a pneumatic system, energy is stored and transmitted using compressed air to power actuators and control valves. The air is pressurized by a compressor, stored in reservoirs, and released to create motion and force. This medium makes the system quick to respond and often lighter and simpler than liquid-based systems, though the force depends on pressure and the size of the moving piston because air is compressible. This is distinct from electrical power, which uses electricity to drive devices; hydraulic systems, which use an incompressible fluid to transmit force; and manual mechanical action, which relies on human effort.