Which is more elastic: rubber or steel?

What is the Young's modulus and bulk modulus for a perfect rigid body?

For four wires made of the same material,if the same force is applied,in which wire will the increase in length be maximum?

$A$ stretched wire of a material whose Young's modulus $Y = 2 \times 10^{11} \ Nm^{-2}$ has Poisson's ratio $\sigma = 0.25$. Its lateral strain is $\varepsilon_l = 10^{-3}$. The elastic energy density of the wire is:

Two steel wires of same length $L$ but radii $r$ and $2r$ are connected together end to end and tied to a wall as shown. The force $F$ stretches the combination by $10 \ mm$. How far does the junction point $A$ move (in $mm$)?

When the temperature of a wire of length $L_0$ is increased by $T$,what is the energy density? The volume expansion coefficient of the wire is $\gamma$ and the Young's modulus is $Y$.