Question

If 'S' is stress and 'Y' is Young's modulus of a wire material, then energy stored in the wire per unit volume, is?

• A. $\frac{S^2}{2Y}$
• B. $\frac{2Y}{S^2}$
• C. $\frac{S}{2Y}$
• D. $2S^{2}Y$

Answer 1

The correct option is A $\frac{S^2}{2Y}$

Energy stored in the wire per unit volume = U = (1/2)*Stress*Strain
Also, Strain= (Stress /Y)
Therefore,
On substituting The expression for Strain in the first equation:
U = $\frac{S^2}{2Y}$