Limit of Proportionality on Spring Graph

Steps:

• Examine the force-extension graph for a straight-line region where extension is directly proportional to force.
• Identify the point where the graph deviates from linearity and begins to curve upward.
• This deviation marks the end of Hooke's law applicability (F = kx).
• Locate the labeled point at this transition, which is C.

Why C is correct:

• C marks the end of the straight-line portion, where proportionality ceases per Hooke's law, as force no longer produces proportional extension.

Why the others are wrong:

• A: Lies within the initial linear region, where proportionality still holds.
• B: Remains in the straight-line section before deviation.
• D: Occurs beyond the limit, in the non-proportional curved region.

Final answer: C