The magnetic field of a bar magnet
Lesson details
Learning outcome
I can plot a magnetic field around a bar magnet.
Key learning points
- The needle of a plotting compass lines up with the magnetic field of a magnet.
- A magnetic field line can be followed from the north–seeking pole to the south–seeking pole of a magnet.
- Arrows on magnetic field lines show the direction in which the north–seeking pole of another magnet would be forced.
- The magnetic field of a bar magnet is symmetrical.
- Magnetic field lines do not cross over and are continuous.
Keywords
Magnetic field - A region where a magnetic material experiences a force.
Plotting compass - A small compass that can show the field of a magnet.
North-seeking magnetic pole - The end of a compass needle which points to the north of Earth.
South-seeking magnetic pole - The end of a compass needle which points to the south of Earth.
Field line - An imaginary line that shows the direction and shape of a magnetic field.
Common misconception
The magnetic field is only at the poles of a magnet.
Provide opportunities for pupils to plot magnetic field lines around a bar magnet and to experiment with a second magnet, as described in the teacher tip.
Teacher tip
You can use a visualiser to demonstrate the action of field lines by holding in place a bar magnet on a sheet of paper with its field lines plotted around it, and gently pushing the north–seeking pole of a second magnet towards it, which is forced along the field line it is on.
Equipment
Plotting compass, bar magnet, A4 plain paper, iron filings.
Content guidance
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of the following statements about magnets is correct?
Q2.Which of the following statements about a south–seeking pole are correct?
Q3.If a magnet is broken into two pieces, how many poles will there be in total?
Q4.Which of the following statements about the magnetic force is correct?
Q5.What does the part of a bar magnet, shown in the image, do?

Q6.Which of the following statements is correct?
Assessment exit quiz
6 Questions
Q1.Which of the following materials can be used to show the magnetic field of a magnet?
Q2.How are iron filings affected by a magnet?
Q3.What causes a compass needle to point towards Earth's north pole?
Q4.Which of the following correctly describes the direction in which the needle of a plotting compass will point?
Q5.In which direction do magnetic field lines point?
Q6.Which of the following statements about magnetic field lines are correct?
To help you plan your 9 science lesson on: The magnetic field of a bar magnet, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 9 science lesson on: The magnetic field of a bar magnet, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 science lessons from the Magnets and electromagnets unit, dive into the full secondary science curriculum, or learn more about lesson planning.