Stress-strain: load a wire until it breaks
"Stress-strain: load a wire until it breaks" is a free, interactive Class 11 Physics simulation for NEET and JEE, built on the lesson "Hooke's law and the stress-strain curve" in Mechanical Properties of Solids. Stretch it with the slider and watch the dot run along the stress-strain curve. Press Remove load at any point to see what the wire does when the force goes. O-A obeys Hooke's law; up to B the wire still recovers; beyond B it keeps a permanent set; D is the ultimate tensile strength and E is fracture. D and E close together means brittle, far apart means ductile. JEE Main asked 31 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
From the lesson Hooke's law and the stress-strain curve in Mechanical Properties of Solids. Change the values and watch what happens.
In JEE Main
42 shifts analysed
31 questions from Mechanical Properties of Solids across the 42 JEE Main shifts Lumi has analysed (2017–2026).
The idea behind it
NCERT §8.3, §8.4
- Hooke's law: for small deformations, stress is proportional to strain. Stress = k × strain, where the constant k is the modulus of elasticity.
- Hooke's law is empirical. It holds for most materials over small strains, but some materials never show a straight-line relation.
- In a tensile test a wire or test cylinder is loaded in steps and its strain recorded; stress (applied force per unit area) is then plotted against strain.
- O to A: a straight line. Hooke's law holds and the body recovers fully when unloaded, so it behaves elastically.
- A to B: stress and strain are no longer proportional, yet the body still recovers on unloading. B is the yield point, also called the elastic limit, and the stress there is the yield strength σy.
- Beyond B the strain grows fast for small increases in stress. If the load is removed at a point C between B and D, the strain does not return to zero: the body has a permanent set, a plastic deformation.
- D marks the ultimate tensile strength σu. Past D the strain keeps growing even under a smaller force, and the wire fractures at E.
- D and E close together: the material is brittle. D and E far apart: the material is ductile.
- Elastomers such as rubber and the elastic tissue of the aorta can be stretched to large strains and still recover. Their elastic region is huge, yet Hooke's law fails over most of it and there is no well-defined plastic region.
Questions
3 answers
- What does the "Stress-strain: load a wire until it breaks" simulation show?
- Stretch it with the slider and watch the dot run along the stress-strain curve. Press Remove load at any point to see what the wire does when the force goes.
- Does JEE Main ask questions from Mechanical Properties of Solids?
- Yes. JEE Main asked 31 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
- Is this simulation free?
- Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Hooke's law and the stress-strain curve" in Mechanical Properties of Solids (Class 11 Physics).
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