AQA AS Level Physics Paper 2, June 2024: Question 24

1 mark · Easy difficulty · Multiple Choice

Identify the true statement regarding material deformation and brittle fracture among the given options.

Practise this question

Question

Multiple choice question 24 asking 'Which statement is true?' worth 1 mark. Four options are provided: A, 'A brittle fracture occurs after little or no elastic deformation.'; B, 'A brittle fracture occurs after little or no plastic deformation.'; C, 'In a plastic deformation, energy stored is proportional to stress.'; D, 'In a plastic deformation, stress is proportional to strain.' Each option has a selection box next to it.
Question text

24 Which statement is true?

[1 mark]

A A brittle fracture occurs after little or no elastic deformation.

B A brittle fracture occurs after little or no plastic deformation.

C In a plastic deformation, energy stored is proportional to stress.

D In a plastic deformation, stress is proportional to strain.

Mark scheme

Show the mark scheme The mark scheme table shows question number 24 with the correct answer indicated as B, corresponding to the statement 'A brittle fracture occurs after little or no plastic deformation.'

24 B A brittle fracture occurs after little or no plastic deformation.

How to answer it

Properties of Materials: Brittle Fracture

Question 2.4 • 1 Mark

What this question tests

This question assesses your precise definitions of mechanical properties of materials, specifically distinguishing between elastic and plastic deformation, and understanding the characteristic behavior of brittle materials right up to the point of fracture.

Exam Question Breakdown

Identifying the True Statement

✅ Correct Answer: Option B

A brittle fracture occurs after little or no plastic deformation.

Mark Awarded: 1 / 1 for selecting B.

💡 Key Knowledge

  • Brittle: A brittle material breaks under stress with little to no plastic deformation (e.g., glass, ceramics, cast iron).
  • Plastic Deformation: Permanent deformation remains after the force is removed. Brittle materials snap before this occurs significantly.
  • Elastic Deformation: Even brittle materials undergo elastic deformation (stretching where they return to their original shape) up to their breaking point, so Option A is incorrect.

🧠 Exam Technique

Read every option carefully before committing. Examiners often test common mix-ups between "elastic" and "plastic" deformation terms. Know your definitions word-for-word from the specification!

❌ Common Errors

  • Confusing elastic and plastic: Students often choose Option A because they assume brittle materials don't stretch at all. In reality, they obey Hooke's law elastically up until a sudden fracture.
  • Assuming linearity in plastic flow: Options C and D wrongly link energy or stress proportionally across plastic deformation, where behaviour is non-linear and permanent.

Topics

Physics · 3.4 Mechanics and materials

Question and mark scheme from the AQA AS Level Physics examination, Paper 2, June 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.