Mechanical Aptitude Knowledge Questions and Answers 3

Question 1

What is the function of a governor in a mechanical system?

Accepted Answer

To automatically regulate speed

Answer

A governor automatically regulates the speed of a machine, typically an engine or turbine, by adjusting fuel supply or load in response to speed changes. It maintains a desired operating speed despite varying loads.

Question 2

What is the difference between ferrous and non-ferrous metals?

Accepted Answer

Ferrous metals contain iron, non-ferrous do not

Answer

Ferrous metals contain iron as their primary component (steel, cast iron, wrought iron), while non-ferrous metals do not contain significant iron (aluminum, copper, brass, titanium). Ferrous metals are typically magnetic and susceptible to rust.

Question 3

What mechanical principle explains why longer wrenches require less effort to turn a bolt?

Accepted Answer

Mechanical advantage through leverage

Answer

A longer wrench provides greater mechanical advantage because torque equals force multiplied by the perpendicular distance from the pivot (T = F × d). Increasing the wrench length increases the moment arm, so less force is needed to produce the same torque.

Question 4

What is the purpose of tempering steel after it has been hardened?

Accepted Answer

To reduce brittleness while maintaining hardness

Answer

Tempering is a heat treatment performed after hardening that reduces brittleness while retaining much of the hardness. Hardened steel is extremely hard but brittle; tempering heats it to a moderate temperature to relieve internal stresses and achieve a balance of hardness and toughness.

Question 5

In a belt-and-pulley system, what happens if the driven pulley is larger than the driving pulley?

Accepted Answer

The driven pulley rotates slower with more torque

Answer

When the driven pulley is larger than the driving pulley, the driven pulley rotates slower but with greater torque. The speed ratio is inversely proportional to the diameter ratio, providing a speed reduction and torque multiplication.

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Knowledge Questions and Answers 3