The young's modulus of the material of a rod is `20xx10^(10)` pascal. When the longitudal strain is `0.04%`. The energy stored per unit volume is

Options

A. `4xx10^(-3) J//m^(3)`
B. `8xx10^(3) J//m^(3)`
C. `16xx10^(-3) J//m^(3)`
D. `16xx10^(3) J//m^(3)`

Answer

D

Explanation

`Y = ("stress")/("strain") , (E)/(V) = (1)/(2) xx Y xx ("strain")^(2)`