The elastic limit is the maximum stress a material can withstand while still returning to its original shape once the load is removed. Beyond this point, permanent plastic deformation occurs.
What does the shear force at a point in a beam represent?
A The internal force causing sliding
B The internal force causing compression
C The external load applied
D The internal force causing bending
Shear force in a beam is the internal force that causes layers of the material to slide relative to one another. It is calculated at various points along the beam and affects the beam’s stability.
What is Hooke’s Law primarily used to describe?
A Shear deformation
B Stress and strain relationship
C Plastic deformation
D Stress concentration
Hooke’s Law describes the linear relationship between stress and strain within the elastic limit of a material. It is expressed as σ = Eϵ, where σ is stress, E is the modulus of elasticity, and ϵ is strain.
What happens when a material experiences tensile stress?
A The material is compressed
B The material shrinks
C The material elongates
D The material undergoes shear deformation
Tensile stress occurs when a material is stretched or pulled, causing it to elongate. The material’s molecules are drawn apart, resulting in an increase in length along the direction of the applied force.
Which of the following is a property of a plastic material?
A It is always brittle
B It can deform without returning to its original shape
C It does not deform under stress
D It can only undergo elastic deformation
Plastic materials can undergo permanent deformation. Once they are deformed beyond their elastic limit, they do not return to their original shape, which makes them ideal for molding and forming applications.
What does the bending moment at a point in a beam depend on?
A The load and distance from the support
B The beam’s material
C The beam’s temperature
D The beam’s length
The bending moment is the internal moment that causes bending of the beam. It depends on the applied load and the distance from the point where the moment is being calculated to the support.
What is torsion in a material?
A Shear deformation caused by axial loading
B Stretching due to tensile forces
C Twisting caused by torque
D Bending due to external loads
Torsion is the twisting or rotational deformation that occurs when a torque or twisting force is applied to a material, such as a shaft. This results in shear stress that acts parallel to the material’s cross-section.
Which material property describes its ability to return to its original shape after stress removal?
A Ductility
B Toughness
C Plasticity
D Elasticity
Elasticity is the property of a material to return to its original shape after the applied stress is removed. Materials like rubber and steel exhibit elastic behavior within certain limits.
What is plastic deformation?
A Permanent change in shape
B Reversible deformation
C Instantaneous fracture
D Slow deformation under constant stress
Plastic deformation occurs when the stress exceeds the material’s yield strength, causing it to permanently change shape. This type of deformation is irreversible and does not recover after the load is removed.
What is the main function of a shear force diagram?
A To measure the bending moment at points
B To show the distribution of internal shear forces
C To calculate the deflection of a beam
D To show external applied forces
A shear force diagram visually represents the internal shear forces acting on a beam at various points. It helps to determine the variation of shear force along the length of the beam and is used for design analysis.
What is the primary cause of failure in brittle materials?
A Excessive strain
B High ductility
C Sudden application of stress
D High temperature
Brittle materials, such as glass or concrete, fail suddenly when stress is applied beyond their strength. Unlike ductile materials, they do not undergo significant plastic deformation before breaking.
What is the definition of elastic deformation?
A Deformation that is permanent
B Deformation that increases stress
C Deformation caused by high temperature
D Deformation that returns to its original shape
Elastic deformation is reversible deformation that occurs when a material is subjected to stress. When the stress is removed, the material returns to its original shape, and no permanent deformation remains.
What is the effect of axial loading on a material?
A Compression or stretching along the material’s axis
B Twisting along the material’s length
C Bending perpendicular to the material’s length
D Shearing along the material’s surface
Axial loading applies force along the length of a material, causing either compression (if the material is being pushed together) or tensile stress (if the material is being stretched).
What does the term “yield point” refer to?
A The point where a material fractures
B The point where a material transitions from elastic to plastic deformation
C The point of maximum stress
D The point of zero stress
The yield point is the point on the stress-strain curve where a material transitions from elastic deformation (reversible) to plastic deformation (permanent). Beyond this point, the material will not return to its original shape.
What is the primary function of the modulus of rigidity (shear modulus)?
A To measure a material’s resistance to compression
B To measure a material’s resistance to bending
C To measure a material’s resistance to shear deformation
D To measure a material’s ability to return to its original shape
The modulus of rigidity, or shear modulus, measures a material’s resistance to shear deformation when a torque or lateral force is applied. It is used to analyze the behavior of materials subjected to shear stresses.