Q1. Stress is defined as:

1. Force × area
2. Internal resisting force per unit area
3. Deformation per unit length
4. Force per unit volume

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Answer: B. Internal resisting force per unit area

Stress = internal resisting force / cross-sectional area, with units N/m² (Pa).

Q2. The SI unit of stress is:

1. Newton
2. Pascal (N/m²)
3. Joule
4. Newton-metre

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Answer: B. Pascal (N/m²)

Stress has units of force per area = N/m² = Pascal.

Q3. Strain is:

1. Measured in pascals
2. A dimensionless ratio
3. Measured in newtons
4. Force per area

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Answer: B. A dimensionless ratio

Strain = change in dimension / original dimension, so it is dimensionless.

Q4. Shear strain is best described as:

1. A normal deformation
2. An angular deformation (radians)
3. A change in volume
4. A force

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Answer: B. An angular deformation (radians)

Shear strain measures angular distortion and is expressed in radians.

Q5. Poisson’s ratio is the ratio of:

1. Longitudinal to lateral strain
2. Lateral strain to longitudinal strain
3. Stress to strain
4. Shear to normal stress

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Answer: B. Lateral strain to longitudinal strain

Poisson’s ratio ν = − lateral strain / longitudinal strain.

Q6. Engineering (nominal) stress is computed using the:

1. Instantaneous area
2. Original cross-sectional area
3. Mean area
4. Surface area

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Answer: B. Original cross-sectional area

Engineering stress uses the original area; true stress uses the instantaneous area.

Q7. The ratio of change in volume to original volume is called:

1. Linear strain
2. Shear strain
3. Volumetric strain
4. Lateral strain

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Answer: C. Volumetric strain

Volumetric strain = ΔV/V = sum of the three linear strains (εx + εy + εz).

Q8. In a tensile test beyond yield, true stress is ____ engineering stress:

1. Less than
2. Equal to
3. Greater than
4. Unrelated to

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Answer: C. Greater than

As the actual area reduces (necking), true stress exceeds engineering stress.