A metallic rod of length `'L'` and cross-section `'A'` has Young's modulus `'Y'` and coefficent of linear expansion `'alpha'`. If the rod is heated to a temperature. 'T'` the energy stored per unit volume is:

Options

A. `(1)/(2) Y alpha^(2) T^(2)`
B. `(1)/(2) Y A alpha^(2) T^(2)`
C. `(1)/(2) Y A alpha T`
D. `(1)/(2)Y A^(2) alpha^(2) T^(2)`

Answer

A