A beams having a double cantilever attached at mid span is showing in the figure. The nature of forces in beam $$'ab'$$ is

A cantilever beam of tubular section consists of 2 materials copper as outer cylinder and steel as inner cylinder. It is subjected to a temperature rise of $$20^\circ C$$ and $$\alpha_{copper}\;>\;\alpha_{steel}$$ the stresses developed in the tubes will be

In a linear elastic structural element

The maximum value of Poisson's ratio for an elastic material is