======Magnetic Fields with Iron Filings======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Alternative titles:** Magnet Field Patterns
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====Summary====                   
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====Procedure====  
  - Place a sheet of paper or transparency over a bar magnet to prevent filings from sticking to it.
  - Trace the outline of the bar magnet and mark its north and south poles.
  - Lightly sprinkle iron filings evenly over the paper.
  - Gently tap the paper to help the filings align with the magnetic field lines.
  - Observe the pattern that forms, particularly the curves from north to south poles.
  - Record observations and compare with compass tracing patterns made earlier.
  - Discuss and write hypotheses explaining why the filings form the observed shapes.



====Links==== 
Magnetic Fields – Observing Magnetic Force - Next Generation Science: 
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Plotting Magnetic Field Lines - QuantumBoffin: 
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📄 Iron Filings and Magnetic Field Lines - lasp.colorado.edu: [[https://lasp.colorado.edu/wp-content/uploads/2011/08/P1-2_3D_field.pdf]]\\


====Variations====
  * Place two bar magnets side by side with opposite poles facing each other and observe how the fields combine.
  * Place two bar magnets with like poles facing each other and observe the field repulsion pattern.
  * Use horseshoe magnets to see how their fields differ from straight bar magnets.
  * Demonstrate on an overhead projector using a transparency to show the whole class at once.



====Safety Precautions====
  * Keep a sheet of paper or transparency between the magnet and the iron filings to prevent filings from sticking directly to the magnet.
  * Handle iron filings carefully; they are messy and difficult to clean up if spilled.
  * Keep filings away from eyes, mouth, and electronic devices.
  * Wash hands thoroughly after handling iron filings.




====Questions to Consider====
  * What do the iron filings reveal about the magnetic field? (They align along field lines showing the field’s shape and direction.)
  * Why do the filings form curved lines between the poles of the magnet? (Magnetic field lines extend from the north pole to the south pole in curved paths.)
  * How does the pattern compare to the earlier compass tracing activity? (They should match, since both reveal the same field lines.)
  * Why do the filings act like tiny magnets? (Each filing becomes a temporary magnet when exposed to the bar magnet’s field and aligns along the field.)
  * What happens when two magnets are placed with opposite poles facing each other? (The fields combine, showing strong attraction.)
  * What happens when two magnets are placed with like poles facing each other? (The fields repel, and the filings show areas where lines bend away from each other.)