Exam-style question
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During a practical to find the Young modulus, the measured extension of a copper wire is 0.0015 m when a force of 300 N is applied. The wire’s cross‑sectional area is 1.5 mm² and its original length is 0.75 m. Which of the following is the correct value of the Young modulus?.
- A.1.2 × 10¹⁰ Pa
- B.2.4 × 10¹⁰ Pa
- C.3.6 × 10¹⁰ Pa
- D.4.8 × 10¹⁰ Pa
Model answer
What a good answer should say
- 2.4 × 10¹⁰ Pa.
- the correct option
Explanation
Why this works
The correct answer is 2.4 × 10¹⁰ Pa. This supports Required practical 4: determine the Young modulus of a material.
in The Young modulus because it uses the required mechanics relationship directly. The other options are less suitable because they confuse a different force, motion, energy, momentum, or materials concept.
Common mistake
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