250+ TOP MCQs on Stress Strain Diagrams & Mechanical Properties of Engineering Materials and Answers

Machine Design Multiple Choice Questions on “Stress Strain Diagrams & Mechanical Properties of Engineering Materials”.

1. Which of the following parameters can be obtained by tension test of a standard specimen?
a) Proportional Limit
b) Yield Strength
c) Percentage Reduction in area
d) All of the mentioned
Answer:a
Clarification: Tension test determines the parameters related to stress strain curve and also reduction and elongation in area and length can be found respectively.

2. Proportional Limit is defined as the stress at which the stress strain curves begins to deviate from the straight line.
a) True
b) False
Answer:a
Clarification: Proportional limit is the point of deviation in stress strain curve.

3. Which of the following is the definition of Compliance?
a) Inverse of Rigidity
b) Inverse of Stiffness
c) Proportional to elastic Limit
d) None of the mentioned
Answer:b
Clarification: Compliance is a parameter which is the inverse of stiffness.

4. Yield strength is defined as the maximum stress at which a marked increase in elongation occurs without increase in________
a) Load
b) Strength
c) Toughness
d) Hardness
Answer:a
Clarification: Yield strength is the strength at which strain increases. Now as the strength is constant, therefore load is constant.

5. For the materials which do not exhibit a well-defined yield points, the yield strength is defined as the stress corresponding to a permanent set of how much percentage of gauge length?
a) 0.1
b) 0.2
c) 0.3
d) 0.4
Answer:b
Clarification: Generally for all the practical purpose, an offset of 0.2% of gauge length is considered.

6. Proof strength is defined as the stress which will produce a permanent extension of how much percentage in the gauge length of the standard test specimen.
a) 0.1
b) 0.2
c) 0.3
d) 0.4
Answer:a
Clarification: Proof strength is used in design of fasteners. It corresponds to 0.1% permanent deformation of gauge length.

7. All engineering materials are plastic.
a) True
b) False
Answer:a
Clarification: Yes all the existing engineering materials are plastic to some extent.

8. Which of the following are true about plasticity?
a) Permanent Deformation
b) Ability to retain deformation under load or after removal of load
c) Plastic deformation is greater than elastic deformation
d) All of the mentioned
Answer:d
Clarification: This is the basic definition of plasticity.

9. Which of the following is measure of stiffness?
a) Modulus of elasticity
b) Modulus of plasticity
c) Resilience
d) Toughness
Answer:a
Clarification: Stiffness is the ability of material to resist deformation under external load. Hence it is measured by modulus of elasticity.

10. Which of the following facts are true for resilience?
a) Ability of material to absorb energy when deformed elastically
b) Ability to retain deformation under the application of load or after removal of load
c) Ability of material to absorb energy when deformed plastically
d) None of the mentioned
Answer:a
Clarification: Toughness is ability to store energy till proportional limit during deformation and to release this energy when unloaded.

11. Modulus of resilience is defined as
a) Strain energy per unit volume
b) Strain energy per unit area
c) Independent of strain energy
d) None of the mentioned
Answer:a
Clarification: Modulus of resilience is strain energy per unit volume.

12. Which of the following are true for toughness
a) Ability of material to absorb energy before fracture
b) Measured by Izod & Charpy test
c) Decreases with the increase in temperature
d) All of the mentioned
Answer:d
Clarification: Toughness is measure of energy stored till fracture occurs. With rise of temperature, molecular bonds weakens and fracture occurs at a lesser load, hence area under stress strain curve decreases.

13. Malleability increases with temperature while ductility decreases with temperature.
a) True
b) False
Answer:a
Clarification: Malleability is the deformation under compressive load and hence with rise in temperature, the deformation increases and hence malleability increases.

14. Hardness is
a) Surface property
b) Resistance to abrasion
c) Depends upon resistance to plastic deformation of the material
d) All of the mentioned
Answer:d
Clarification: Hardness is a surface property which is the resistance of material to surface indentation. It depends upon resistance to plastic deformation.