The strain energy stored in a solid circular shaft in torsion, subjected to shear stress ($$\tau $$), is:
(Where, G = Modulus of rigidity for the shaft material)

A. $$\frac{{{\tau ^2}}}{{2G}}$$ × Volume of shaft

B. $$\frac{\tau }{{2{\text{G}}}}$$ × Volume of shaft

C. $$\frac{{{\tau ^2}}}{{4G}}$$ × Volume of shaft

D. $$\frac{\tau }{{{\text{4G}}}}$$ × Volume of shaft

Answer: Option C