EIAT Mechanical Comprehension 4

Question 1

A safety gear (progressive safety) on an elevator is activated by:

Accepted Answer

Overspeed detected by the governor rope

Answer

The governor monitors cab speed and, if overspeed occurs, trips the governor rope which mechanically activates the safety gear to grip the guide rails.

Question 2

What is the primary purpose of a buffer at the bottom of an elevator pit?

Accepted Answer

Absorb the kinetic energy of the cab or counterweight at the end of travel

Answer

Buffers (oil or spring type) are energy-absorbing devices designed to stop a descending cab or counterweight that travels beyond its normal limit.

Question 3

In a simple pulley system with a fixed pulley and a movable pulley, the mechanical advantage is:

Accepted Answer

2

Answer

A system with one fixed and one movable pulley provides a mechanical advantage of 2, meaning half the effort is needed to lift the load.

Question 4

Viscosity of hydraulic oil in an elevator system affects:

Accepted Answer

The flow resistance and heat generation in the hydraulic circuit

Answer

Higher viscosity increases flow resistance and heat generation; lower viscosity reduces efficiency and can cause leakage — proper viscosity ensures smooth, efficient operation.

Question 5

A driven gear has 60 teeth and the driving gear has 20 teeth. The gear ratio (output:input) is:

Accepted Answer

3:1 speed reduction

Answer

Gear ratio = driven teeth / driving teeth = 60/20 = 3:1, meaning the output shaft turns at one-third the speed of the input shaft.

EIAT - Elevator Industry Aptitude Test Practice Test

EIAT - Elevator Industry Aptitude Test Practice Test

EIAT Mechanical Comprehension 4