Q. 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
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
Explanation
(d) $Stress = \frac{Force}{area}$
In the present case, force applied and area of cross-section of wires are same, therefore stress has to be the same
$Strain = \frac{Stress}{Y}$
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
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.