$A$ wire is hanged from the ceiling without any weight below it. Would there be any stress in the wire?

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

Select the correct alternative$(s)$.

Explain the spring-ball model of the elastic behavior of solids.

The reason for the change in shape of a regular body is

The length of a metallic wire is $\ell_{1}$ when the tension in it is $T_{1}$. It is $\ell_{2}$ when the tension is $T_{2}$. The original length of the wire will be ...... .