A student wants to find out which end of an unmarked bar magnet is the north pole. They have access to a compass. Describe how the student could identify the north pole of the bar magnet using the compass, and explain how the compass indicates which end is the north pole.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
1. The student holds the compass close to one end of the bar magnet.
2. The compass needle, a small permanent magnet, is deflected.
3. The north pole of the bar magnet repels the north‑seeking pole of the needle.
4. The end that causes the needle’s north pole to point away from the magnet is the north pole of the bar magnet.
2. The compass needle, a small permanent magnet, is deflected.
3. The north pole of the bar magnet repels the north‑seeking pole of the needle.
4. The end that causes the needle’s north pole to point away from the magnet is the north pole of the bar magnet.
Examiner tips
- Use the command word ‘describe’ – list the steps in order. Show the relationship between the poles (north–north repulsion). Explain the direction of the needle’s movement relative to the magnet’s end.
Common mistakes
- Confusing the compass needle’s north pole with the bar magnet’s north pole. Failing to state that the needle’s north pole is repelled. Not indicating that the end causing the needle to point away is the north pole.
Mark scheme (4 marks)
- The student brings/holds the compass near one end of the bar magnet
- The compass needle (a small permanent magnet) will be deflected / will point in a particular direction
- The north pole of the bar magnet repels the north-seeking (north) pole of the compass needle
- The end of the bar magnet that causes the north pole of the compass needle to point away from it (i.e. is repelled) is the north pole of the bar magnet
Key terms in this question
Related
- All Eduqas GCSE Physics revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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