EIT Materials Science 2

Question 1

Young's modulus (modulus of elasticity) is defined as:

Accepted Answer

Stress divided by strain in the elastic region

Answer

Stress divided by strain in the plastic region

Answer

Ultimate tensile strength divided by yield strength

Answer

The slope of the stress-strain curve at fracture

Question 2

What is the approximate Young's modulus for structural steel?

Accepted Answer

200 GPa

Answer

10 GPa

Answer

70 GPa

Answer

400 GPa

Question 3

In a Brinell hardness test, hardness is determined by:

Accepted Answer

Measuring the diameter of a spherical indentation from a hardened ball

Answer

Measuring the depth of a diamond cone indentation

Answer

Measuring the rebound height of a dropped ball

Answer

Measuring the width of a surface scratch

Question 4

What does a standard Charpy impact test measure?

Accepted Answer

Energy absorbed during fracture of a notched specimen

Answer

Hardness at low temperature

Answer

Tensile strength at high strain rates

Answer

Fatigue life under cyclic loading

Question 5

The endurance limit in fatigue testing is best described as:

Accepted Answer

The stress amplitude below which a material can theoretically endure infinite cycles

Answer

The maximum stress a material can withstand before fracture

Answer

The number of cycles to failure at a given stress

Answer

The minimum stress that causes plastic deformation

Question 6

A material that undergoes significant plastic deformation before fracture is classified as:

Accepted Answer

Ductile

Answer

Brittle

Answer

Elastic

Answer

Resilient

Question 7

Percent elongation in a tensile test is used to quantify:

Accepted Answer

Ductility of the material

Answer

Elastic stiffness of the material

Answer

Fracture toughness

Answer

Ultimate tensile strength