Investigating magnetic fields

Investigating magnetic fields

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
a) Aim: To investigate the magnetic field around a horseshoe magnet. The magnetic field can be shown by using lines that represent the force of the magnet. The force can be seen when iron filings are held over a magnet. An example is shown below.
 


Bar magnet showing the magnetic field lines
 
   
Place the horseshoe magnet onto a flat surface. Place a sheet of paper over it so it sits on the top of the magnet. Then sprinkle some iron filings onto the paper. Draw in the magnetic field lines you see onto the diagram below.
 

 
 
 
 

 
 
 
 
Horseshoe Magnet
 
 
b)
Aim: To investigate the magnetic field around two magnets
 
  i)
Place two bar magnets so that they are end to end about 4 cm apart. Have similar poles face each other. Place the sheet of paper over the two magnets and then sprinkle some iron filings onto the paper.
Draw the magnetic field lines you see onto the diagram below.
  ii)
Repeat part i), except have the poles that are not alike facing each other.
Draw the magnetic field lines you see onto the diagram below.
c)
Describe what is happening when the two South Poles are facing each other.
 
 
 
 
 
d)
Describe what is happening when the South and the North Pole face each other.
 
 
 
 
 
e)
Explain what would happen to the magnetic field lines if the two North Poles of the magnet faced each other.
 
 
 
 
Task administration: 
[Equipment: 2 × bar magnets; horseshoe magnet; iron filings; sheet of white paper.]

  • This task requires students to investigate the magnetic field around different shaped magnets using iron filings.
  • This resource has two parts; they can be completed separately or together.
Level:
4
Curriculum info: 
Science, Investigating in science, Physical World
Keywords: 
physical inquiry, forces, magnetic fields, magnets
Description of task: 
For this practical task students investigate the magnetic fields that exist around a horseshoe magnet. Students then use two bar magnets to investigate what happens when similar and unlike poles are facing each other.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Interpret representations
This resource provides opportunities to discuss and compare the patterns made from two representations of something invisible, the force fields (patterns made with iron filings and lines on a diagram).
 
Science capabilities: 
Interpret representations
Making Better Sense: 
Magnetic Fields
Answers/responses: 
a)  

NOTE: There are other field lines but the answer must include the field line between the two ends of the horseshoe magnet.
b) i)
 
 
 
 
 
 
 
ii)

NOTE: The key part of the student answer is to show repelling between the South Poles.

NOTE: The key part of the student answer is to show attraction between the North and South Poles.
c)    The magnetic fields/magnets are repelling each other.
d)   There is attraction between the poles.
e)   The poles would repel.