Copper of fixed volume V is drawn into wire of length ι. When this wire is subjected to a constant force F, the extension produced in the wire is ∆ι. Which of the following graphs is a straight line?
Δl versus 1/l
Δl versus l2
Δl versus 1/l2
Δl versus l
As V=Al . . . .(i)
where A is the area of cross - section of the wire.
Young's modulus, Y=(F/A)(Δl/l)=FlAΔl
Δl=FlYA=Fl2YV (Using (i)
Hence, the graph between Δl and l2 is a straight line.