Question

1. The area below the stress-strain curve represents:

	a.	The toughness for a brittle material
	b.	The energy absorbed by the material at yield
	c.	The resilience for a ductile material
	d.	The resilience for a brittle material
	e.	The energy absorbed by the material at fracture

2. Impact is a measure of the ability of a material to absorb energy during elastic deformation

True

False

3. A material is behaving plastically when

		Stress persists after the applied strain is removed
		Strain returns to zero after the applied stress is removed
		Stress returns to zero after the applied strain is removed
		Strain persists after the applied stress is removed

4. Ductility of a material measures the amount of strain it reaches at failure.

True

False

5. True stress and true strain are used by scientists when a material is developed.

True

False

Answer 1

1) option e is correct.

Energy absorbed by the material under fracture. That is toughness but thoughness will not be there for Brittle materials.

2) false

Because, impact is a measure of load which is applied from certain height.

And energy absorbed under elastic deformation is resilience.

3)stress returns to zero after applied strain is removed. Because we know that stress is directly proportional to strain.

4)true

Ductility is an indication of how much plastic strain a material can withstand before it breaks.

5)true

Because true stress and true strain gives the accurate results.