Question

According to Hooke’s law of elasticity, if stress is increased, then the ratio of stress to strain:
A) Becomes zero.
B) remains constant.
C) Decreases
D) Increases

Answer 1

Stress is the mechanical force which is acted on a body per unit area, due to this force body can deform i.e. change its shape permanently or temporarily. And strain is the measure of degree at which object is deformed. Here we have asked the ratio of stress to strain, when stress is increased, so we will discuss the Hooke’s law and find the answer.
Formula used:
$E=\dfrac{\text{stress}}{\text{strain}}$

Complete answer:
According to Hooke’s law, stress is directly proportional to strain i.e. amount of force applied per unit area will be directly proportional to the degree of deformation and there ratio is a constant which is given as
$E=\dfrac{\text{stress}}{\text{strain}}$
Here E is the modulus of elasticity.
When stress is increased that force will increase too. And greater the force applied greater will be deformation i.e. greater the strain. Hence the ratio will be balanced
Hence according to Hooke’s law, even if we increase the stress or strain the ratio of stress to strain remains constant.

Option B is the correct answer.

Additional information:
Elasticity means the body under stress deforms but when stress is removed it comes back to its original shape. Although elasticity also has a limit. If an object is stretched beyond its limit of elasticity the body won’t come back to its original shape.
The material which has the greatest elasticity is steel. Steel is more elastic than rubber.

Note:
Although modulus of elasticity is constant but it varies from material to material i.e. two different materials will have different values of modulus of elasticity. Hooke’s law is applicable within the limit of elasticity. The modulus of elasticity has the same unit as stress as strain is dimensionless quantity.