EIAT Gears, Pulleys, and Levers 5

Question 1

What is 'backlash' in a gear system?

Accepted Answer

The small gap between meshing gear teeth

Answer

Backlash is the slight clearance between mating gear teeth, necessary for lubrication and thermal expansion but too much causes imprecision.

Question 2

A compound lever system uses two levers in series. If each lever has a mechanical advantage of 4, the total mechanical advantage is:

Accepted Answer

16

Answer

In a compound lever system, the total mechanical advantage equals the product of each individual lever's MA: 4 × 4 = 16.

Question 3

A traction elevator uses rope friction over the drive sheave rather than a drum winder. The primary advantage is:

Accepted Answer

Allowing unlimited travel height without rope length limits

Answer

Traction systems are not limited by rope wound on a drum, enabling skyscraper heights that drum systems cannot achieve.

Question 4

Gear pitch (diametral pitch) refers to:

Accepted Answer

The number of teeth per inch of pitch diameter

Answer

Diametral pitch is the number of gear teeth per inch of pitch diameter and determines whether two gears can mesh together.

Question 5

If the effort arm of a lever is 3 feet and the load arm is 1 foot, and you apply 40 lb of effort, what load is lifted?

Accepted Answer

120 lb

Answer

MA = effort arm ÷ load arm = 3 ÷ 1 = 3; Load = 40 × 3 = 120 lb.

EIAT - Elevator Industry Aptitude Test Practice Test