Strength of Materials Multiple Choice Questions on “Properties of Strain”.
1. The property of a material by which it can be drawn into thin wires is?
a) Malleability
b) Plasticity
c) Ductility
d) Elasticity
Answer: c
Clarification: The ductile material can be drawn into wires because it can resist large deformation. Malleability is the property by which it can be made into thin sheets.
2. If the material has identical elastic properties in all directions, it is called ____________
a) Elastic
b) Isotropic
c) Plastic
d) Homogeneous
Answer: b
Clarification: An homogeneous material is that with uniform composition. An elastic and plastic are different on the criteria.
3. Why is the strain the fundamental property but not the stress?
a) Because it is dimensionless
b) Because it is a ratio
c) Because it’s value is calculated in the laboratory
d) No stress is the fundamental property
Answer: c
Clarification: The stress is the fundamental property because it is calculated in the laboratory. It is a non dependable value.
4. The material in which large deformation is possible before absolute failure by rupture is called ____________
a) Plastic
b) Elastic
c) Brittle
d) Ductile
Answer: d
Clarification: The ductile material can be drawn into wires because it can resist large deformation before it fails.
5. What is a creep?
a) Gradual increase of plastic strain with time at constant load
b) Gradual increase of elastic strain with time at constant load
c) Gradual increase of plastic strain with time at varying load
d) Gradual increase of elastic strain with time at varying load
Answer: a
Clarification: Creep is the property by virtue of which a metal specimen undergoes additional deformation with the passage of time under sustained loading within elastic limit. It is permanent in nature and cannot be recovered after removal of load, hence is plastic in nature.
6. If the material has different elastic properties in perpendicular directions, it is called ____________
a) Elastic
b) Isotropic
c) Orthotropic
d) Plastic
Answer: c
Clarification: Isotropic material has the same elastic properties but ortho tropic material has the same.
7. Which one of the following pairs is NOT correctly matched?
a) Visco-elastic – small plastic zone
b) Orthotropic material – different properties in three perpendicular directions
c) Strain hardening material – stiffening effect felt at some stage
d) Isotropic material – same physical property in all directions at a point
Answer: a
Clarification: Visco-elastic material exhibit a mixture of creep and elastic after effects at room temperature. Thus their behaviour is time dependent. Materials with different properties in different directions are called anisotropic. Orthotropic material is a special case of an anisotropic material in three mutually perpendicular directions. However, these are symmetric about any axis.
8. The phenomenon of slow extension of materials having a constant load, I.e. increasing with the time is called
a) Creeping
b) Yielding
c) Breaking
d) None of the mentioned
Answer: a
Clarification: The creeping is the phenomenon of deformation in materials which have been under load for several time. When the load is put on the material, initially it deforms but when the load is not removed, it causes a small amount of deformation which increases with time.