A uniform wire of length $L$ and radius $r$ is twisted by an angle $\alpha$. If modulus of rigidity of the wire is $\eta$, then the elastic potential energy stored in wire, is ………

If $x$ longitudinal strain is produced in a wire of Young's modulus $y,$ then energy stored in the material of the wire per unit volume is

Weight is suspended to the end of elastic spring its increased length depends upon what ?

When load of $5\,kg$ is hung on a wire then extension of $3\,m$ takes place, then work done will be ……. $joule$

A wire of length $50\, cm$ and cross sectional area of $1$ sq. mm is extended by $1\, mm.$ The required work will be      $(Y = 2 \times {10^{10}}\,N{m^{ – 2}})$