Question

Choose the correct option.

• A. For perfect plastic material, there is no restoring force.
• B. Young's modulus for a perfectly plastic body is zero.
• C. Steel is more elastic than rubber.
• D. All of the above are correct.

Answer 1

The correct option is D All of the above are correct.

Perfectly plastic body cannot regain its shape even when the deforming force is removed because of absence of restoring force.
As restoring force is zero, there is no stress present. Therefore, Young's modulus for perfectly plastic body is zero.

It can be said that for a given amount of stress, the strain produced in the steel is comparatively smaller than the strain produced in the rubber. Therefore, with the help of Young's modulus, it can be concluded that steel has greater elasticity than rubber.