The load versus elongation graph for four wires is shown. The thinnest wire is

Step-by-step solution

Using ( Y = F / A L / L ) Cross-section area of the wire ( A = R ² ) where ( R ) is the radius of the wire ( Y = F R ² L L ) ( F = R ² Y L L ) Thus Slope of load vs elongation graph, ( s = R ² Y L ) ( s R ² ) Now from the graph shown, OA has the least slope and hence the least radius. Thus ( OA ) represents the thinnest wire.