Stress, Strain and Young's Modulus

Question 1

What is cohesion?

Answer 1

the force that holds particles together in a solid or liquid

Question 2

What is stress in materials science?

Answer 2

Stress is the force applied per unit area within materials, typically measured in Pascals (Pa).

Question 3

What is the formula for calculating stress?

Answer 3

Stress is calculated using the formula: Stress = Force / Area.

Question 4

What is strain?

Answer 4

Strain is the measure of deformation representing the displacement between particles in a material.

Question 5

What is the formula for calculating strain?

Answer 5

Strain is calculated using the formula: Strain = Change in Length / Original Length.

Question 6

True or False: Strain is a dimensionless quantity.

Answer 6

True.

Question 7

What is Young’s modulus?

Answer 7

Young’s modulus is a measure of the stiffness of a material, defined as the ratio of stress to strain.

Question 8

What is the formula for Young’s modulus?

Answer 8

Young’s modulus (E) is calculated using the formula: E = Stress / Strain.

Question 9

What units are used for Young’s modulus?

Answer 9

Young’s modulus is typically measured in Pascals (Pa).

Question 10

What does a high Young’s modulus indicate about a material?

Answer 10

A high Young’s modulus indicates that the material is stiff and resistant to deformation.

Question 11

Fill in the blank: The relationship between stress and strain is linear in the ______ region.

Answer 11

elastic.

Question 12

What is the elastic limit?

Answer 12

The elastic limit is the maximum stress that a material can withstand without undergoing permanent deformation.

Question 13

True or False: Beyond the elastic limit, materials will return to their original shape after the load is removed.

Answer 13

False.

Question 14

What is plastic deformation?

Answer 14

Plastic deformation is the permanent distortion of a material that occurs when the stress exceeds the elastic limit.

Question 15

What is tensile stress?

Answer 15

Tensile stress is the stress that occurs when a material is subjected to a stretching or pulling force.

Question 16

What is compressive stress?

Answer 16

Compressive stress is the stress that occurs when a material is subjected to a squeezing or pushing force.

Question 17

What is shear stress?

Answer 17

Shear stress is the stress that occurs when forces are applied parallel to a surface.

Question 18

What is the significance of the slope of the stress-strain curve?

Answer 18

The slope of the stress-strain curve in the elastic region represents Young’s modulus.

Question 19

What is the difference between elastic and plastic behavior in materials?

Answer 19

Elastic behavior is reversible deformation, while plastic behavior is permanent deformation.

Question 20

Fill in the blank: Materials with low Young’s modulus are considered ______.

Answer 20

flexible.

Question 21

What happens to a material when it reaches its yield strength?

Answer 21

When a material reaches its yield strength, it begins to deform plastically and will not return to its original shape.

Question 22

True or False: Young’s modulus is constant for all materials.

Answer 22

False.

Question 23

What type of material typically has a high Young’s modulus?

Answer 23

Metals generally have a high Young’s modulus.

Question 24

What is the relationship between stress and strain in the plastic region?

Answer 24

In the plastic region, the relationship between stress and strain is non-linear.

Question 25

What does it mean if a material is ductile?

Answer 25

A ductile material can undergo significant plastic deformation before rupture.

Question 26

What does it mean if a material is brittle?

Answer 26

A brittle material fractures with little or no plastic deformation.

Question 27

Fill in the blank: The point at which a material permanently deforms is known as the ______ point.

Answer 27

yield.

Question 28

What is ultimate tensile strength?

Answer 28

Ultimate tensile strength is the maximum stress a material can withstand while being stretched or pulled before breaking.

Question 29

What is the difference between force and stress?

Answer 29

force is external applied force to the material and stress is the internal resistance of the material to the applied force

Question 30

What does it mean if a body/ material resist deformation ?

Answer 30

Applied force on the body/ material is less than the body's maximum stress capacity of the material

Question 31

What is direct stress?

Answer 31

Stress induced in a material due to a force acting perpendicular to the object

Question 32

What is indirect stress?

Answer 32

Stress which results from multiple forces rather than a singular force

Question 33

Name 4 types of strain

Answer 33

1.Volumetric strain ( due to changes in pressure ) 2.Compressive strain ( due to compressive stress ) 3.Tensile strain ( caused by tensile stress ) 4. Shear strain ( caused by shear strain )