A mild steel wire of length \(2L\) and cross-sectional area \(A\) is stretched, well within the elastic limit, horizontally between two pillars (figure). A mass \(m\) is suspended from the mid-point of the wire. Strain in the wire is:

    

1. \( \dfrac{x^2}{2 L^2} \) 2. \(\dfrac{x}{\mathrm{~L}} \)
3. \(\dfrac{x^2}{L}\) 4. \(\dfrac{x^2}{2L}\)