Physics Elasticity Question 122

Question: A copper wire and a steel wire of the same diameter and length are connected end to end and a force is applied, which stretches their combined length by 1 cm. The two wires will have

[MP PMT 1992]

Options:

A) Different stresses and strains

B) The same stress and strain

C) The same strain but different stresses

D) The same stress but different strains

Show Answer

Answer:

Correct Answer: D

Solution:

$ r=\frac{r}{r} $ . In the present case, force applied and area of cross-section of wires are same,

Therefore stress has to be the same. $ r=\frac{r}{Y} $ Since the Young’s modulus of steel wire is greater than the copper wire, therefore, strain in case of steel wire is less than that in case of copper wire.