Q. If S is stress and Y is Young’s modulus of material of a wire, the energy stored in the wire per unit volume is
A) $2S^{2}Y$
B) $\frac{S^{2}}{2Y}$
C) $\frac{2Y}{S^{2}}$
D) $\frac{S}{2Y}$
Explanation
(b) Energy stored in the wire $= \frac{1}{2}stress \times strain \times volume$
and ${Young}^{'}s\ modulus = \frac{Stress}{Strain}$
⟹ $strain = \frac{S}{Y}$
$\frac{Energy\ stored\ in\ \ wire}{Volume} = \frac{1}{2} \times stress \times strain$
$= \frac{1}{2}S \times \frac{S}{Y} = \frac{S^{2}}{2Y}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.