NEIEP Mechanics Practice Exam

What supports a hydraulic elevator?

1. The chain system

2. The column of oil inside the jack

3. The weight of the elevator itself

4. A series of cables

The correct answer is: The column of oil inside the jack

A hydraulic elevator operates using a system where a hydraulic piston is used to lift and lower the elevator car. This process relies on the principles of fluid mechanics, specifically hydraulics. The correct answer highlights that the column of oil inside the jack is essential for the functioning of a hydraulic elevator. When the hydraulic system is activated, a pump sends pressurized oil into the cylinder, which moves the piston upward. This action raises the elevator car. When the elevator needs to descend, the oil is released back into the reservoir, allowing gravity to bring the car down slowly and safely. The other options describe components used in different types of elevators or mechanical systems. For example, while chains and cables may be part of traction elevators, they are not relevant to the hydraulic system. The weight of the elevator itself does play a role in overall system dynamics and safety, but it is not the primary mechanism that provides the lifting force in a hydraulic elevator.