What type of power system uses a liquid as the power transmission medium?

The correct answer is the hydraulic system, which utilizes a liquid—typically oil or water—as the transmission medium for power. In a hydraulic system, power is transmitted through the movement of the liquid in a bounded space, allowing for force to be effectively applied. The incompressibility of liquids enables precise control over motion and force, which is especially beneficial in applications requiring significant lifting capabilities or torque generation.

Hydraulic systems can be found in various machinery and equipment, such as excavators, forklifts, and industrial presses. The liquid medium allows for the transfer of energy with minimal energy loss, making hydraulic systems efficient in applications that require heavy lifting or intricate manipulations.

In contrast, pneumatic systems use gas as the transmission medium, mechanical systems rely on solid components and physical connections, and electrical systems transmit power using electrical energy. Each of these alternatives has distinct characteristics and applications, but the defining feature of a hydraulic system is its use of liquid to transmit power effectively.