It is intended to estimate the elastic properties $E,G,$

$u$ of a metal by performing tensile and torsion tests on identical specimens of diameter $10$ mm and gauge length $120$ mm $.$ In the tensile test, it is observed that an axial force of $6$ kN causes the gauge length to increase by $0\mathrm{.}1$ mm $,$ whereas in the torsion test, a torque of $12$ Nm causes a twist $($relative rotation of the ends$)$ of the gauge length of $3\mathrm{.}1.$

Show that these results are not consistent with linear elasticity $($Hooke$\text{'}$s law$).$ One of your lab partners suggests that yielding may have occurred in one of the tests. If so$,$ which test is the most likely to have involved yielding?