A wire of length `1 m` and radius `1mm` is subjected to a load. The extension is `x`.The wire is melted and then drawn into a wire of square cross - section of side `2 mm` Its extension under the same load will be

Options

A. `(pi^(2) x)/(16)`
B. `pi x^(2)`
C. `(pi^(2) x)/(3)`
D. `(pi)/(x)`

Answer

A

Explanation

Volume = constant, `pi r^(2) l = a^(2) l^(1), e = (Fl)/(YV)`