Permanent Magnets and Magnetic Fields

Active exploration helps students visualize invisible forces and correct misconceptions about magnetism. Through hands-on mapping and modeling, learners connect abstract domain theory to tangible evidence, building durable understanding of permanent magnets and their fields.

• Year 10
• Physics
• 4 activities
• 25 min–45 min

Learning Objectives

1. Compare the magnetic field patterns generated by a bar magnet and a horseshoe magnet, identifying similarities and differences in field line distribution.
2. Construct accurate diagrams illustrating the magnetic field lines around a bar magnet, showing directionality from north to south poles.
3. Explain the behavior of permanent magnets, including attraction and repulsion, by referencing the alignment of magnetic domains.
4. Identify the poles of a permanent magnet and predict the direction of force between two magnets based on pole orientation.

Gallery Walk

⏱ 25 min·Small Groups

Iron Filings Mapping: Bar Magnet Fields

Secure a bar magnet under white paper. Students sprinkle fine iron filings evenly across the surface, then tap the paper lightly to align filings. They observe and sketch the curved field lines, noting denser regions near poles. Repeat with a horseshoe magnet for comparison.

Prepare & details

Explain how the alignment of magnetic domains explains the behavior of permanent magnets.

Facilitation Tip: During Iron Filings Mapping, remind students to tap the tray gently to allow filings to settle without clumping, ensuring clear field line patterns emerge.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Gallery Walk

⏱ 30 min·Pairs

Compass Plotting: Field Line Tracing

Pairs position a plotting compass near the north pole of a bar magnet and mark the needle's north-pointing tip. Move the compass so the south tip touches the previous mark, repeating to trace full field lines. Label directions and compare patterns from multiple lines.

Prepare & details

Compare the magnetic field patterns around a bar magnet and a horseshoe magnet.

Facilitation Tip: During Compass Plotting, have students place the compass near the magnet first to observe initial alignment before tracing, preventing rushed or inaccurate lines.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Gallery Walk

⏱ 35 min·Small Groups

Domain Alignment Simulation: Straw Model

Provide students with bundles of drinking straws painted north-south. In small groups, they align straws haphazardly, test 'attraction', then realign them fully and retest. Discuss how domain alignment creates net magnetism, linking to permanent magnet properties.

Prepare & details

Construct a diagram showing the magnetic field lines around a bar magnet.

Facilitation Tip: During Domain Alignment Simulation, ask students to rotate their straws slowly to simulate domain shifting, linking physical movement to magnetic behavior.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Stations Rotation

⏱ 45 min·Small Groups

Stations Rotation: Magnet Comparisons

Set up stations with bar, horseshoe, and ring magnets plus iron filings and compasses. Groups rotate every 10 minutes, mapping fields at each and noting pole proximity effects. Conclude with whole-class sharing of sketches.

Prepare & details

Explain how the alignment of magnetic domains explains the behavior of permanent magnets.

Facilitation Tip: During Station Rotation, set a two-minute timer at each station so students rotate efficiently and focus on collecting comparative data.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Teaching This Topic

Teach this topic by starting with concrete experiences before introducing domain theory, reversing the common sequence. Avoid spending too much time on abstract models before students have observed real fields. Research shows that when students first manipulate materials and map fields, they are more ready to understand domain alignment as an explanatory tool rather than a starting point.

What to Expect

Students will accurately map magnetic fields, explain pole behavior through domain alignment, and distinguish between ferromagnetic attraction and non-magnetic materials. They will use evidence from activities to revise initial ideas about isolated poles and field shape.

Watch Out for These Misconceptions

Common Misconception

During Iron Filings Mapping, watch for students who claim a magnet can have a single pole if they see more filings on one side.

What to Teach Instead

After Iron Filings Mapping, have students test both ends with a compass. Ask them to break a soft magnet bar in half (if available) and test each new end, guiding them to observe that each piece always has two poles.

Common Misconception

During Compass Plotting, watch for students who draw straight lines between poles, ignoring the curved shape of the field.

What to Teach Instead

During Compass Plotting, remind students to place the compass at multiple points around the magnet, not just between the poles. Ask them to note how the needle orients at each position to emphasize the closed-loop nature of the field.

Common Misconception

During Station Rotation, watch for students who assume all metals are magnetic after seeing some metals respond to a magnet.

What to Teach Instead

During Station Rotation, provide a tray with labeled samples of iron, nickel, cobalt, aluminium, copper, and stainless steel. Ask students to classify each material and discuss why only some are attracted, connecting their observations to the concept of ferromagnetic domains.

Assessment Ideas

Exit Ticket

After Iron Filings Mapping, give students a blank diagram of a bar magnet. Ask them to sketch the field lines, label the poles, and write one sentence explaining whether two identical bar magnets will attract or repel when placed end to end.

Quick Check

After Station Rotation, hold up each magnet type and describe a scenario, such as 'Which magnet creates a field that is strongest between its poles?' Students respond with one finger for bar magnet or two fingers for horseshoe magnet.

Discussion Prompt

After Domain Alignment Simulation, pose the question: 'If you cut a permanent magnet into four pieces, how many north and south poles would you have?' Facilitate a discussion using their straw models to demonstrate domain alignment and pole formation in each piece.

Extensions & Scaffolding

• Challenge students to predict and then test the field pattern of two bar magnets placed side by side with like poles facing.
• For students who struggle, provide pre-labeled field diagrams to trace over during Iron Filings Mapping, focusing their attention on accuracy rather than initial drawing.
• Have advanced students research how MRI machines use strong magnetic fields and relate domain alignment in permanent magnets to the alignment of hydrogen atoms in the body.

Key Vocabulary

Magnetic Domain	A region within a magnetic material where the magnetic alignment of atoms is in a uniform direction. In permanent magnets, these domains are aligned to create a net magnetic field.
Magnetic Field	The region around a magnetic material or a moving electric charge within which the force of magnetism acts. It is visualized using magnetic field lines.
Magnetic Field Lines	Imaginary lines used to represent the direction and strength of a magnetic field. They emerge from the north pole and enter the south pole of a magnet.
North Pole	One of the two poles of a magnet, conventionally defined as the pole that points towards the Earth's geographic North Pole. Magnetic field lines emerge from this pole.
South Pole	The other pole of a magnet, conventionally defined as the pole that points towards the Earth's geographic South Pole. Magnetic field lines enter this pole.