This set of Mechanical Behaviour Multiple Choice Questions & Answers (MCQs) focuses on “Tensile Properties”.
1. What is the elastic modulus of steel?
a) 69-79 GPa
b) 41-45 GPa
c) 190-217 GPa
d) 330-360 GPa
View Answer
Explanation: Steel has an elastic modulus of 190-217 GPa. It has E higher than aluminum and magnesium alloys. But lower than tungsten and molybdenum alloys.
2. What is the elastic modulus of titanium alloys?
a) 150-170 GPa
b) 180-214 GPa
c) 80-130 GPa
d) 41-45 GPa
View Answer
Explanation: Titanium alloys have the elastic modulus in the range of 80 to 130 GPa. It is greater than aluminum and magnesium alloys but lesser than steel.
3. What is the order of elastic modulus for Nickel alloys, Lead alloys, Molybdenum alloys, alumina?
a) Pb < Mo < Ni < Al2O3
b) Ni < Pb < Mo < Al2O3
c) Pb < Ni < Mo < Al2O3
d) Pb < Ni < Al2O3 < Mo
View Answer
Explanation: Lowest elastic modulus is of Lead and its alloys of 14-18 GPa. Ni and Mo alloys have elastic modulus of 180-214 and 330-360 GPa respectively. Al2O3 has highest E among the four of 415 GPa.
4. What property enhances with a decrease in E?
a) Flexibility
b) Stiffness
c) Hardness
d) UTS
View Answer
Explanation: The lower the elastic modulus of material, the more flexible it is. Bending of material becomes easier. On the other hand, stiffness decreases.
5. What is the unit of elastic modulus?
a) Mohs
b) GPa
c) Kg
d) N
View Answer
Explanation: Elastic modulus is expressed in GPa. Mohs is the unit used for hardness. Stress is measured in MPa.
6. When applied stress is of shear type, the modulus of elasticity is known as ___
a) Bulk modulus
b) Modulus of resilience
c) Shear modulus
d) Stiffness
View Answer
Explanation: When the type of stress applied is shear, E is known as shear modulus. It is also known as modulus of rigidity. Stiffness is measured in terms of E.
7. Which of the following tensile property is dimensionless?
a) Tensile stress
b) Elastic modulus
c) True strain
d) Toughness
View Answer
Explanation: True strain is dimensionless property. Tensile strength and elastic modulus are measured in MPa and GPa respectively.
8. What is a factor which controls the elastic modulus?
a) Alloying
b) Heat treatment
c) Interatomic forces
d) Cold working
View Answer
Explanation: On a constant temperature and pressure, E only is function of two factors. First is type of interatomic forces. Second is arrangement of atoms or crystal structure.
9. Stress should not exceed ___ when in service.
a) Yield strength
b) Tensile strength
c) Fracture strength
d) Toughness
View Answer
Explanation: Above yield strength, material starts to deform plastically. It causes a change in dimensions and properties of a material. So material should be used below it.
10. Stress should not exceed ___ when in mechanical working
a) Yield strength
b) Tensile strength
c) Fracture strength
d) Toughness
View Answer
Explanation: Mechanical working process consists of plastic deformation. So it is performed above yield strength. But it is limited below tensile strength so as to avoid fracture.
11. Ductility of material is its ability to flow plastically under compressive load.
a) True
b) False
View Answer
Explanation: Ductility is a tensile property. It is studied under tensile loading. It is the ability to plastic flow without rupture.
12. Work per unit volume of the material is a known modulus of toughness.
a) True
b) False
View Answer
Explanation: Toughness is measured by the amount of work per unit volume of the material under static loading. Work per unit volume of material is called modulus of toughness.
Sanfoundry Global Education & Learning Series – Mechanical Behaviour & Testing of Materials.
To practice all areas of Mechanical Behaviour & Testing of Materials, here is complete set of 1000+ Multiple Choice Questions and Answers.
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