The work done per unit volume to stretch the length by 1% of a wire with cross sectional area of 1 `"mm"^(2)` ' will be [Given `Y=9xx 10^(11)' N//m^(2)]`

Options

A. `4.5 xx 10^(7)` J
B. `9xx 10^(11) ` J
C. `4.5 xx 10^(11)` J
D. `9xx 10^(7)` J

Answer

A

Explanation

Energy = `U = (1)/(2) xx Y xx ("strain")^(2) = (1)/(2)xx 9xx 10^(11) xx ((1)/(100))^(2)`
`U = 4.5 xx 10^(7) ` Joule