Question

In case of steel wire or a metal wire, the elastic limit is reached when:
A. the wire just breaks.
B. the load is more than the weight of wire.
C. elongation is no longer proportional to the tension.
D. none of these.

Answer 1

Hint: The above problem can be resolved using the concepts and the fundamentals of Hooke's law. Hooke's law says that when a material is applied, some magnitude of the external load, such that this load is causing some change in the linear dimension of the material. The stress developed due to the application of this load will cause the dependency of the change in the linear dimension of the material.

Complete step by step answer:
When a steel wire is subjected to some external load, the stress is developed in the steel wire. And this stress causes some elongation, which is directly proportional to the magnitude of stress developed within the body. When the steel wires show direct proportionality of the stress and the corresponding strain, this point is known as the point of elasticity. But after a specific point, the steel wire will lose its elasticity, and at this point, the stress developed due to the applied load will no longer be proportional to the elongation or the strain. This means, now, at this point, the steel wire will be deformed permanently on the application of the load , and the change in the length of the wire will show an inverse relation with the applied load, and this particular point is known as the elastic limit of the material.

So, the correct answer is “Option C”.

Note:
Try to understand the concept of Hooke's law and the applications of Hooke's law. The fundamentals must be cleared like stress, strain, along with a significant relationship among them.Remember in the case of steel wire, the elastic limit is reached when the elongation is inversely proportional to the tension