Two different types of rubber are found to have the stress-strain curves as shown below in figure. The area of the stress-strain curve of a material is numerically equal to the work done in loading the material and then unloading it.

1) Since for the above curves, Hooke’s law is not obeyed as the curve is not a straight line hence such type of curve are called as elastic hysteresis as the materials do not retrace curve during unloading.

 2) Rubber B is preferred because area of loop B is more than that of A which shows more absorption power for vibrations which is useful in machinery.

3) Since hysteresis loop is a direct measure of heat dissipation, hence rubber A is preferred over B so to minimize the heating in the car tyres.