Name an application where hydraulic systems are frequently used.

Hydraulic systems are prominently used in construction equipment like excavators due to their ability to generate high amounts of force and power with relatively compact components. Excavators rely on hydraulic cylinders to perform various tasks such as digging, lifting, and moving materials. The hydraulic fluid transmits force from the engine to the hydraulic cylinders, enabling the heavy machinery to efficiently lift and manipulate heavy loads with precision and control.

In contrast, the other options typically rely on different mechanisms. For instance, office printers and household vacuum cleaners generally use electric motors, while automobiles primarily integrate a mix of mechanical and electronic systems for propulsion and operation, rather than focusing predominantly on hydraulic systems. Therefore, the use of hydraulic systems is particularly vital in construction equipment, underscoring their advantages in applications requiring significant power and control.