Free Mechanical Aptitude Question and Answers

Question 1

Which of the following techniques uses a generating process to produce gear?

Accepted Answer

Hobbing

Answer

Hobbing is a specialized machining process that uses a rotating cutting tool, called a hob, to generate gear teeth. It's a continuous generating process where the hob and the gear blank rotate in a synchronized manner, allowing for efficient and accurate production of various types of gears.

Question 2

Which of the following properties of the working substance will change as a result of reversible heat exchange?

Accepted Answer

Entropy

Answer

Entropy is a thermodynamic property that quantifies the disorder or randomness of a system. During a reversible heat exchange, the change in entropy of the working substance is directly related to the amount of heat transferred and the absolute temperature at which it occurs. This fundamental concept is central to the second law of thermodynamics.

Question 3

The term for the increase in hardness brought on by cold working is

Accepted Answer

Work hardening

Answer

Work hardening, also known as strain hardening, is the phenomenon where a metal becomes harder and stronger due to plastic deformation at temperatures below its recrystallization temperature (cold working). This process increases the density of dislocations within the material's crystal structure, impeding their movement and thus increasing the material's resistance to further deformation.

Question 4

The machining of continuously formed chips

Accepted Answer

Mild steel

Answer

Continuously formed chips are characteristic of machining ductile materials, which deform plastically without fracturing. Mild steel is a ductile material, allowing for the formation of long, continuous chips during cutting operations. Brittle materials, like cast iron, tend to produce discontinuous chips.

Question 5

The factors that most affect the cutting tool's tool life are

Accepted Answer

Cutting speed

Answer

Cutting speed is the most significant factor affecting a cutting tool's life. Higher cutting speeds generate more heat at the tool-workpiece interface, leading to accelerated tool wear and a substantial reduction in tool longevity. While other factors like feed and depth of cut also play a role, their impact is typically less pronounced than that of cutting speed.

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Test Practice Test

Free Mechanical Aptitude Question and Answers