NEET Physics: Stress-strain relationship Practice Questions

Correct answer: A — Poisson's Ratio

Poisson's ratio (σ) is the ratio of transverse strain to axial strain, describing the lateral contraction when subjected to axial stress.

Correct answer: A — Change in length per unit original length

Strain is defined as the relative deformation or change in shape resulting from the applied stress. It is calculated as the change in dimension divided by the original dimension.

Correct answer: C — Yield point

Plastic deformation begins when the material yields, which is typically defined by the yield point, marking the transition from elastic to plastic behavior.

Correct answer: B — Stress

Stress is defined as the internal force acting per unit cross-sectional area within a material, representing the internal restoring forces developed when the material is subjected to an external load.

Correct answer: C — Stiff

Young's modulus (Modulus of Elasticity) is a measure of the material's resistance to elastic deformation; a higher value indicates greater stiffness.

Correct answer: B — Young's Modulus

The ratio of longitudinal stress (σ) to longitudinal strain (ε) in the elastic region is the definition of Young's Modulus (Y = σ/ε).

Correct answer: B — Elastic region

Hooke's law describes the linear relationship between stress and strain, which is only valid in the elastic region of the material's behavior.

Correct answer: A — The stress

Since Stress (σ= F/A) is proportional to the applied force (F) for a constant area (A), the resulting strain (change in length) is directly proportional to the applied force.

Correct answer: A — Elastic Region

Hooke's Law (σ= Eε) applies specifically to the linear elastic region of a material's stress-strain curve.

Correct answer: B — Stress

Stress (σ) is defined as the internal force acting on a cross-sectional area (Force/Area), representing the internal resisting forces per unit area.

Correct answer: A — Stress is doubled

Stress (σ) is defined as Force (F) divided by Area (A). If F is doubled and A is constant, the stress must also be doubled.

Correct answer: C — The work done to cause the deformation

The elastic energy stored is proportional to the work done (W = F · d) required to cause the elastic deformation, which is related to the area under the stress-strain curve.

Correct answer: B — Stress

Stress is defined as the internal resistance force applied to a unit cross-sectional area within a body, which is the fundamental measure of the force per unit area.

Correct answer: A — Hooke's Law

Elastic deformation is governed by Hooke's Law, which states that stress is directly proportional to strain within the elastic limit.

Correct answer: D — Elastic Limit

The Elastic Limit is the maximum stress a material can withstand while still behaving elastically; deformation beyond this point is permanent (plastic deformation).