APT APT Mechanical Aptitude

Question 1

If gear A has 20 teeth and gear B has 10 teeth, and gear A rotates at 100 RPM, how fast does gear B rotate?

Accepted Answer

200 RPM

Answer

When meshed gears have a 2:1 tooth ratio, the smaller gear spins twice as fast; 100 × (20/10) = 200 RPM.

Question 2

Which type of lever has the fulcrum between the effort and the load?

Accepted Answer

First-class lever

Answer

A first-class lever has the fulcrum positioned between the effort force and the load (e.g., a seesaw).

Question 3

A pulley system with 4 pulleys requires an effort force to lift a 400-pound load. Approximately how much effort is needed?

Accepted Answer

100 lbs

Answer

A 4-pulley system provides a mechanical advantage of 4, reducing required effort to 400 ÷ 4 = 100 lbs.

Question 4

What is the purpose of a torque wrench?

Accepted Answer

To measure and apply a specific tightening force

Answer

A torque wrench measures and applies a precise amount of rotational force (torque) to fasteners.

Question 5

Water flows through a pipe that narrows from 4 inches to 2 inches in diameter. What happens to the water's speed?

Accepted Answer

It increases

Answer

According to the continuity principle, fluid speeds up when flowing through a narrower pipe to maintain constant flow rate.

APT - Army Personnel Testing Practice Test