Bennett Mechanical Comprehension Practice Test 2025 – The Complete All-in-One Guide to Exam Success!

A hydraulic lift operates based on Pascal's principle, which states that when pressure is applied to a confined fluid, it is transmitted equally in all directions throughout the fluid. This allows a relatively small force applied at one point to be transformed into a larger force at another point.

In this system, both the input and output pistons are filled with hydraulic fluid. When a user applies a small force on the input piston, it generates pressure in the fluid. Since the pressure is constant throughout the hydraulic system, this pressure can be applied through a larger area on the output piston, resulting in a significant increase in force. This principle allows heavy loads to be lifted with minimal effort.

This explanation highlights how a hydraulic lift effectively multiplies force, enabling the lifting of heavy objects with ease, while the other methods listed, like using a vacuum, pulleys, or gears, do not apply to the operation of hydraulic lifts.