STRESS AND STRAIN

Poisson ratio depends on

• Lateral strain

• Stress

• Material of specimen

• None

Answer explanation

It is a material property that describes how a material deforms laterally when stretched or compressed longitudinally.

Stress is a ___ quantity

• Vector

• Scalar

• Tensor

• None of the above

If a piece of material neither expands nor contracts in volume when subjected to stresses, then the Poisson’s ratio must be?

• 0.5
• 1.0
• 0.0
• -0.5

Answer explanation

If a material does not change in volume under stress (i.e., no volumetric strain), this implies it is perfectly incompressible.

In such a case, the Poisson's ratio (ν) is:0.5

When tensile stress is applied axially on a circular rod its

• diameter decreases

• length increases

• Volume decreases

• Both A and B

Answer explanation

When tensile stress is applied axially on a circular rod, the following occurs:

1. Length increases — due to elongation along the axis (longitudinal strain).

2. Diameter decreases — due to lateral contraction (lateral strain).

which one of the following is a unit less factor

• stress

• strain

• young's modulus

• both b and c

Which of the following best describes shear force in a material?

• A force acting perpendicular to the cross-section causing elongation

• A force that changes only the volume of the material

• A force acting parallel to the cross-section causing layers to slide

• A compressive force that shortens the material

Answer explanation

• Shear force acts parallel to the cross-sectional area of a material.

• It causes internal layers to slide past each other

• Unlike normal stress (which causes elongation or compression), shear stress results in shape distortion (change in angle, not volume).

• This force is crucial in materials like bolts, rivets, or beams, which resist sliding failure.

Which of the following material has Poisson's ratio greater than 1?

• Steel

• Cork

• Copper

• None

Answer explanation

Poisson ratio is the ratio between

• Stress and strain

• Lateral and longitudinal strain    

• Longitudinal strain and lateral strain

• Shear stress and shear strain

The deformation per unit length is called

• Stress

• Strain

• Young’s Modulus

• Bulk Modulus

What is the linear strain if a bar 140 cm long stretches out to 142 cm when a load of 5800 kg is applied

• 0.0142857
• 0.0105
• 0.018
• 0.012

Answer explanation