About Deformation of solids in A Level Physics
Deformation of solids is one of the 13 main topics in our A Level Physics (Cambridge (CAIE) 9702) question bank, and about 5% of its real questions come from it. Tayyari Karo has 35 real questions on this topic from 2021 to 2026, from Paper 1, Paper 2; 30 are multiple choice and marked instantly, and the rest are structured questions with a model answer. By difficulty: 17 medium, 10 hard, 8 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
Try 6 real questions
These are real past-paper questions. Think of your answer first, then open the explanation.
May/June 2026 · Paper 1 · Deformation of solids
A metal wire is stretched by a tensile force. The tensile force is increased. The volume of the wire remains constant and the limit of proportionality is not exceeded.
Which quantity remains constant?
- the cross-sectional area of the wire
- the strain of the wire
- the stress in the wire
- the Young modulus of the metal
Show answer and explanation
Answer: D. the Young modulus of the metal
Area, stress and strain all change as the force increases; the Young modulus is a material property and is constant below the limit of proportionality.
October/November 2025 · Paper 1 · Deformation of solids
A wire has an unstretched length of 2.00 m. A stress of 1.6 × 10⁵ Pa is applied to the wire, and the new length of the wire is 2.10 m. The wire obeys Hooke's law. What is the Young modulus of the wire?
- 8.0 × 10³ Pa
- 7.8 × 10⁴ Pa
- 1.5 × 10⁵ Pa
- 3.2 × 10⁶ Pa
Show answer and explanation
Answer: D. 3.2 × 10⁶ Pa
Strain = 0.10/2.00 = 0.05; E = stress/strain = 1.6×10⁵/0.05 = 3.2×10⁶ Pa.
May/June 2024 · Paper 1 · Deformation of solids
When a force of 0.80 N is applied to a spring, the length of the spring is 90 mm. When a force of 1.30 N is applied to the same spring, its length is 115 mm. The spring obeys Hooke's law.
What is the spring constant of the spring?
- 8.9 N m⁻¹
- 10 N m⁻¹
- 11 N m⁻¹
- 20 N m⁻¹
Show answer and explanation
Answer: D. 20 N m⁻¹
k = ΔF/Δx = (1.30 − 0.80)/((115 − 90) × 10⁻³) = 0.50/0.025 = 20 N m⁻¹.
October/November 2024 · Paper 1 · Deformation of solids
A spring of spring constant 30 N m⁻¹ is suspended vertically from its top and obeys Hooke's law. Initially it is neither compressed nor stretched. A mass of 0.50 kg is attached to the bottom and released from rest, falling with negligible friction.
What is the maximum extension of the spring?
- 0.017 m
- 0.033 m
- 0.16 m
- 0.33 m
Show answer and explanation
Answer: D. 0.33 m
By energy conservation, the mass falls until all lost PE converts to EPE: mgx = ½kx², so x = 2mg/k = 2×0.50×9.81/30 ≈ 0.33 m.
October/November 2024 · Paper 1 · Deformation of solids
A spring has an unstretched length of 0.30 m and a spring constant of 400 N m⁻¹. An object is suspended from the spring, deforming it within its limit of proportionality to a new length of 0.50 m.
What is the elastic potential energy stored in the spring?
- 8.0 J
- 16 J
- 40 J
- 50 J
Show answer and explanation
Answer: A. 8.0 J
Extension x = 0.50−0.30 = 0.20 m; EPE = ½kx² = ½×400×0.20² = 8.0 J.
May/June 2022 · Paper 1 · Deformation of solids
Which statement about elastic and plastic deformation must be correct?
- Elastic deformation and plastic deformation are proportional to the applied force.
- Elastic deformation and plastic deformation cause no change in volume.
- Elastic deformation causes heating of the material but plastic deformation does not.
- Elastic deformation is reversible but plastic deformation is not.
Show answer and explanation
Answer: D. Elastic deformation is reversible but plastic deformation is not.
By definition, elastic deformation is reversible (the material returns to its original shape when the force is removed) while plastic deformation is permanent.
