Which statement is true for a metal?

If the volume of a wire remains unchanged when it is stretched,what is the Poisson's ratio for the wire?

$A$ copper wire of cross-sectional area $0.01 \ cm^2$ is under a tension of $22 \ N$. Find the percentage change in the cross-sectional area (Young's modulus of copper $= 1.1 \times 10^{11} \ N \ m^{-2}$ and Poisson ratio $= 0.32$).

Explain Poisson's ratio and show that its value is less than $0.5$.

$A$ wire is stretched such that its volume remains constant. The Poisson's ratio of the material of the wire is

For an elastic material,what is the relationship between Young's modulus $(Y)$ and the modulus of rigidity $(\eta)$?