This set of Strength of Materials Multiple Choice Questions on “Resilience”.
1. The ability of a material to absorb energy when elastically deformed and to return it when unloaded is called __________
a) Elasticity
b) Resilience
c) Plasticity
d) Strain resistance
Answer: b
Clarification: Resilience is the ability of a material to absorb energy when elastically deformed and to return it. Elasticity is the property by which any body regain its original shape.
2. The strain energy stored in a specimen when stained within the elastic limit is known as __________
a) Resilience
b) Plasticity
c) Malleability
d) Stain energy
Answer: a
Clarification: Resilience is the ability of a material to absorb energy when elastically deformed and to return it. Elasticity is the property by which any body regain its original shape. Malleability is the property by which any material can be beaten into thin sheets.
3. The maximum strain energy stored at elastic limit is __________
a) Resilience
b) Proof resilience
c) Elasticity
d) Malleability
Answer: b
Clarification: Proof resilience is the maximum stored energy at the elastic limit. Resilience is the ability of material to absorb energy when elastically deformed and to return it. Elasticity is the property by which any body regain its original shape. Malleability is the property by which any material can be beaten into thin sheets.
4. The mathematical expression for resilience ‘U’ is __________
a) U = σ2/E x volume
b) U = σ2/3E x volume
c) U = σ2/2E x volume
d) U = σ/2E x volume
Answer: c
Clarification: The resilience is the strain energy stored in a specimen so it will be
U = σ2/2E x volume.
5. What is the modulus of resilience?
a) The ratio of resilience to volume
b) The ratio of proof resilience to the modulus of elasticity
c) The ratio of proof resilience to the strain energy
d) The ratio of proof resilience to volume
Answer: d
Clarification: The modulus of resilience is the proof resilience per unit volume. It is denoted by σ.
6. The property by which an amount of energy is absorbed by material without plastic deformation is called __________
a) Toughness
b) Impact strength
c) Ductility
d) Resilience
Answer: d
Clarification: Resilience is the ability of a material to absorb energy when elastically deformed and to return it when unloaded.
7. Resilience of a material plays important role in which of the following?
a) Thermal stress
b) Shock loading
c) Fatigue
d) Pure static loading
Answer: b
Clarification: The total strain energy stored in a body is commonly known as resilience. Whenever the straining force is removed from the strained body, the body is capable of doing work. Hence the resilience is also define as the capacity of a strained body for doing work on the removal of the straining force.
8. A steel has its yield strength of 200N/mm2 and modulus of elasticity of 1x105MPa. Assuming the material to obey hookes law up to yielding, what will be its proof resilience?
a) 0.8 N/mm2
b) 0.4 N/mm2
c) 0.2 N/mm2
d) 0.6 N/mm2
Answer: c
Clarification: Proof resilience = σ2/2E = (200)2 / (2 x 105) = 0.2 N/mm2.
9. A 1m long bar of uniform section extends 1mm under limiting axial stress of 200N/mm2. What is the modulus of resilience for the bar?
a) 0.1 units
b) 1 units
c) 10units
d) 100units
Answer: a
Clarification: Modulus of resilience, u = f2/2E, where E = fL/δL
Therefore, u = 200×1 / 2×1000 = 0.1units.
10. A square steel bar of 10mm side and 5m length is subjected to a load whereupon it absorbs a strain energy of 100J. what is its modulus of resilience?
a) 1/5 N-mm/mm3
b) 25 N-mm/mm3
c) 1/25 N-mm/mm3
d) 5 N-mm/mm3
Answer: a
Clarification: Modulus of resilience is the strain energy stored in the material per unit volume.
u = U/v
= ( 100 x 1000 ) / ( 10 x 10x 5x 1000)
= 1/5 N-mm/mm3.