Question

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

• A. the same stress and strain
• B. the same stress but different strains
• C. the same strain but different stresses
• D. different stress and strains

Answer 1

Answer: (B)

the same stress but different strains

The Same force is applied at the ends of both copper and steel rods and because they have the same diameter, the stress i.e. force/area is the same for both rods.
Stress/strain =Young's modulus
As Young's modulus is different for steel and copper hence, strain comes out to different.