If a uniform brass wire of length 5 m and radius `10^(-3)` m is extended by `10^(-3)`m, then the energy stored in the wire will be
(Young's modulus for brass `=10xx10^(10)N//m^(2)`)

Options

A. `3.14xx10^(-2)J`
B. `3.14xx10^(-1)J`
C. `2xx10^(-3)J`
D. `3.14xx10^(-4)J`

Answer

A

Explanation

`E=(1)/(2) xx y xx ("strain")^(2) xx "volume" `
`=(10^(11) xx 10^(-6) xx 3.14 xx 10^(-6)xx5)/(2xx25) = 3.14 xx 10^(-2)J`.