Which of the following is an amorphous solid?

The length of an elastic string is $a$ metres when the longitudinal tension is $4 \ N$ and $b$ metres when the longitudinal tension is $5 \ N$. The length of the string in metres when the longitudinal tension is $9 \ N$ is

What is stress? Write its unit and dimensional formula.

$A$ force of $1000 \, N$ is required to break a copper wire of radius $1 \, mm$. What force is required to break a copper wire of radius $2 \, mm$?

The load versus elongation graph for four wires of the same material and same length is shown in the figure. The thinnest wire is represented by the line

If the length of a wire is doubled,what is the strain?