Physics · Secondary 3

Active learning ideas

Magnets and Magnetic Fields

Active exploration helps students visualize magnetic forces that operate invisibly, anchoring abstract concepts in concrete evidence. Handling magnets, iron filings, and compasses lets students see forces they cannot observe directly, building accurate mental models through direct experience.

• MOE Syllabus Outcomes
• MOE: Electricity and Magnetism - S3
• MOE: Electromagnetism - S3

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Magnet Pole Interactions

Prepare stations with bar magnets suspended by string, paperclips, and repelling/attracting setups. Groups test like and unlike pole behaviors, measure repulsion distances with rulers, and sketch force directions. Rotate every 10 minutes, then share findings.

Explain how magnetic field lines represent the strength and direction of a magnetic field.

Facilitation Tip

During Station Rotation, circulate to listen for students using terms like ‘repel,’ ‘attract,’ or ‘pole’ to describe interactions, and gently reinforce vocabulary.

What to look for

Provide students with several bar magnets and a collection of small objects (e.g., paper clips, plastic beads, iron filings). Ask them to identify which objects are attracted to the magnets and to predict which poles will attract or repel each other. Observe their interactions and listen to their reasoning.

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

Activity 02

• Experiential Learning
• 30 min · Pairs

Iron Filings Exploration: Field Patterns

Provide bar magnets, white paper, iron filings in shakers. Students sprinkle filings, tap gently to align, observe and draw field lines. Compare patterns for single bar versus two bars end-to-end. Clean up and repeat with horseshoe magnet.

Analyze the interaction between the poles of two permanent magnets.

Facilitation Tip

For Iron Filings Exploration, remind students to tap the tray lightly to settle filings and to sketch patterns immediately to capture the symmetry before filings shift.

What to look for

Give each student a card with a diagram showing two bar magnets. Ask them to draw the magnetic field lines between the magnets, indicating the direction of the field, and to write one sentence explaining whether the magnets will attract or repel based on their pole arrangement.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 03

• Experiential Learning
• 35 min · Pairs

Compass Mapping: Field Lines

Use a bar magnet under paper with compass. Students mark north-pointing directions at intervals, connect to form field lines. Predict and verify closed loops. Discuss line spacing for field strength.

Construct magnetic field patterns around bar magnets using iron filings.

Facilitation Tip

In Compass Mapping, have students align their compasses near each pole and note how the needle’s orientation changes, then discuss why the direction reverses.

What to look for

Pose the question: 'How do we know a magnetic field exists if we cannot see it?' Facilitate a class discussion where students share their observations from using iron filings or compasses, connecting these observations to the concept of magnetic field lines representing invisible forces.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 04

• Experiential Learning
• 25 min · Pairs

Material Testing: Magnetic vs Non-Magnetic

Set out iron, aluminum, plastic, paper samples and magnets. Pairs test attractions, classify materials, hypothesize why iron responds. Record in tables for class discussion.

Explain how magnetic field lines represent the strength and direction of a magnetic field.

Facilitation Tip

While testing materials in Material Testing, encourage students to rate attraction strength on a 1–5 scale to build quantitative thinking about magnetic response.

What to look for

Provide students with several bar magnets and a collection of small objects (e.g., paper clips, plastic beads, iron filings). Ask them to identify which objects are attracted to the magnets and to predict which poles will attract or repel each other. Observe their interactions and listen to their reasoning.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

A few notes on teaching this unit

Teach magnets by starting with hands-on experience, then layer in explanations. Avoid lectures before exploration, as students need to confront their own misconceptions through observation. Use peer discussion to resolve conflicts between observations and prior ideas, and revisit the topic after other labs to deepen understanding.

Students will confidently explain pole interactions, trace field patterns with evidence, and distinguish magnetic from non-magnetic materials. They will use observations to correct misconceptions and articulate why field lines are representations rather than physical structures.

---

Watch Out for These Misconceptions

• During Iron Filings Exploration, watch for students describing field lines as real strings that can be picked up or broken.

  Have students compare their filings patterns to drawings of field lines, then ask them to explain why the filings form loops without touching any strings. Ask, 'What would happen if you tried to lift a string?' to highlight the difference between representation and reality.

• During Station Rotation, listen for students claiming a single pole can exist on a broken magnet fragment.

  Provide halved magnets and let students test the new poles with paper clips. Ask them to predict how many poles a single piece will have and to explain their reasoning using their observations.

• During Material Testing, note students who assume all shiny metals are magnetic or all non-shiny metals are not.

  Create a sorting chart where students categorize metals by response, then discuss electron alignment in ferromagnetic materials. Ask, 'What property makes iron respond but not copper?' to guide them toward atomic structure.

---

Methods used in this brief

• Stations Rotation
• Experiential Learning