2.16 To demonstrate the polarity of bar magnets

Natural sciences

Energy transfers and forces

Educator section

Memorandum

(a) What do you observe? The paper clip also moves upwards and remains hanging in the air under the magnet.

What happens? The paper clip falls back onto the bench.

(b) What happens? The paper clip retains its position in the air.

Conclusion: Magnets are able to attract magnetic materials through non-magnetic materials, but not through magnetic materials.

Explanation: A tin can is made of iron that is covered with a thin layer of tin.

Leaner section

Content

Activity: to demonstrate the polarity of bar magnets [lo 1.2]

Use two bar magnets and six short drinking straws. Bar magnets usually are painted in two colours. One half is red and the other is blue, but some bar magnets are painted silver and red.

Arrange the straws and place the bar magnet on them as indicated in the illustration. Observe what happens.

Observation:__________________________________________________________

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Try to predict what will happen if you arrange the magnets as indicated in the next sketch.

Prediction: ___________________________________________________________

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Observation: __________________________________________________________

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Did you predict correctly? ______________________________________________

Deduction:___________________________________________________________

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This is the law of magnetic poles.

4. magnetic force acting through different materials

Let us see whether a magnet is able to exert attraction through a magnetic material and through a non-magnetic material.

Assessment

Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.2: We know this when the learner conducts investigations and collects data: organises and uses apparatus/equipment or sources to gain and record information;