A student brings an unmagnetised iron nail close to one end of a bar magnet. Explain why the nail is attracted to the magnet, and state what would happen to the nail if it were then brought close to the other pole of the same bar magnet.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Iron is a magnetic material. When placed near a magnet, iron can become temporarily magnetised.
Model answer (4 marks)
The iron nail becomes induced (temporarily magnetised) when it is placed near the bar magnet.
The pole that appears on the end of the nail closest to the magnet is opposite to the pole of the magnet that is facing it.
Because unlike poles attract, the nail is pulled towards the magnet.
If the nail is then brought close to the other pole of the same bar magnet, it will still be attracted to that pole.
The pole that appears on the end of the nail closest to the magnet is opposite to the pole of the magnet that is facing it.
Because unlike poles attract, the nail is pulled towards the magnet.
If the nail is then brought close to the other pole of the same bar magnet, it will still be attracted to that pole.
Examiner tips
- Use the word "induced" or "temporarily magnetised". Explain that the induced pole is opposite to the nearby pole of the magnet. Show the attraction of unlike poles. State that the nail remains attracted to the other pole.
- common_mistakes
- :
- Saying the nail becomes permanently magnetised. Forgetting to mention that the induced pole is opposite. Claiming the nail would be repelled by the other pole.
Mark scheme (4 marks)
- The iron nail becomes induced/temporarily magnetised when placed near the bar magnet
- The pole induced on the end of the nail nearest the magnet is opposite to the pole of the magnet facing it
- Unlike/opposite poles attract, so the nail is pulled towards the magnet
- The nail would still be attracted to the other pole of the bar magnet
Key terms in this question
Related
- All WJEC GCSE Physics (Wales) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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