Which fluid is often used in pneumatic systems for power transmission?

In pneumatic systems, compressed air is the primary fluid used for power transmission. This is because pneumatic systems operate on the principle of using compressed air to create movement and force, allowing machinery and tools to function effectively. Compressed air can be easily stored in tanks and can be rapidly compressed and released, making it highly suitable for applications requiring quick actuation and control. It is also widely available and relatively safe compared to other fluids.

Other fluids listed, such as water, oil, and gasoline, do not serve the same function in pneumatic systems. Water and oil are typically used in hydraulic systems rather than pneumatic systems due to their fluid properties and incompressibility, which are essential for transmitting power through a hydraulic medium. Gasoline is primarily a fuel and is not suitable for use in pneumatic systems, as it does not provide the necessary properties for effective power transmission via compressed air mechanisms.