Background

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The topic “Magnetism” is found in both the Form 3 Penilaian Menengah Rendah (PMR) Science Syllabus and in the Semester 3 Science Teachers’ Training Diploma Syllabus. Most science teachers begin this topic in a very direct and predictable way: the action of one bar magnet on another and the production of magnetic flux patterns by the use of iron filings. The utter predictability of such teaching sequences has caused more yawns to be produced than can be counted.

Objectives

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There are four purposes of incorporating the use of magnetic toys and iron filings in liquids as part of the teaching process. They are:

(i)       To arouse students’ interest as they see magnetism at work.

(ii)     Students are able to appreciate the various magnetic toys available in the market and the science principles involved in their designs.

(iii)    To introduce the game “Guess the Poles” using various magnetic flux patterns that are produced using the bottle of iron filings in liquid method.

(iv)   To challenge students to think analytically and creatively the many daily applications and uses of the concept of "magnetism".

(v)     To emphasize and implement an innovative teaching strategy to further enrich the teaching of ‘magnetism’ in schools, that is, to put into practice the five phases of the constructivist teaching approach as outlined by Scott Dyson and Gater (1987)  in the book “A Constructivist View of Learning and Teaching in Science”.

Benefits for teaching and learning process

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• The magnetic toys do not only complement the teaching and learning process, but they are also an eye-opener for students as they see magnetism at work. These toys are not only cheap but are also easily available in the market. In addition, they can be readily and easily modified by the teacher to enhance the effect of the magnetic field strength.

• As for the sprinkling of iron filings immersed in the bottle of baby oil, they can be readily and easily prepared by the teacher or students. This apparatus will help to prevent the normal mess of iron filings being blown all over the place during experimentation. Moreover, the iron filings can be prevented from rusting in the baby oil for quite a long period of time.

• The “Guess the Poles” game is student-centred and makes learning more enjoyable and meaningful. Thus it increases students’ motivation and interest in magnetism.

• To relate science to everyday life, that is, the use of magnets in daily life.

Apparatus/ materials

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1. Magnetic toys

2. Iron filings immersed in a bottle of baby oil

3. Bar magnets

4. Magnetic burglar alarm

Implementation of the teaching

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A. First Phase: Set Induction

To begin the lesson, the teacher will perform a demonstration involving two sets of magnetic toys (modified by the teacher so that the effect of the magnetic field strength can be seen clearly by the students).

(a) In picture [Refer 7-P1], toy 1 can perform amazing acrobatics acts whereas toy 2 can only perform simple forward and backward motions. Both toys 1 and 2 are of the same type and brand.

(b)   In picture [Refer 7-P2] , toy 3 can swing forward and backwards smoothly whereas toy 4’s swings are very stiff and erratic and it stopped after a short period of time. Both toys 3 and 4 are of the same type and brand.

B.     Second Phase: Brainstorming Session

After watching the demonstration for each set of similar toys, the students will be asked to explain why the toys behave so differently from each other. The teacher will only let them touch and examine the toys if they fail to furnish the required magnetic principles involved, that is “like poles repel and unlike poles attract”.

Note: Most students, after figuring out the answer, will ask permission to examine and play with the above toys.

C.     Third Phase: Restructuring of Ideas

The teacher will then explain to the students that the space surrounding a magnet in which a magnetic force is exerted is called a magnetic field, and that this magnetic force lines can be mapped by using iron filings.

A ‘Guess the Poles’ game will then be introduced. Each group of students will be provided with the following materials: two bar magnets wrapped individually with a paper to conceal their poles, a sprinkling of iron filings immersed in a bottle of baby oil or coconut oil and a white piece of paper.

Place the bar magnet on top of the white piece of paper. By shaking the bottle lightly and then letting its flat surface rest on the bar magnet, the magnetic flux patterns can be seen clearly. The group that formed the most number of patterns with the various combinations of the two magnets and labelling their poles correctly will win the game. A time span of 15 minutes is given for the game. The winning team will be requested to present their endeavours (drawings) in front of the class.

[Refer to 7-P3 and 7-D1]

D.    Fourth Phase: Application of Ideas

After the completion of the above challenging game, the students in their own respective groups will be requested to discuss and list down as many uses of magnets as possible in school, at home and also in their surrounding environment.

Note : Uses of magnets as listed and presented by students include some of the following: pencil case lid, fridge magnet, mosquito netting frame, magnetic wrist-strap for watch, magnetic toys, and book cover-strap lid.

The teacher will then demonstrate the use of the magnetic burglar alarm as a prelude to teaching the topic of electromagnetism during the next lesson.[Refer 7-P4]

E.     Fifth Phase : Recall and Closure

To help students summarize the important information studied so far, the teacher will use a magnetic toy to demonstrate “the floating and spinning object in the air” experiment and the students will be requested to answer the following question:

“Explain with the aid of a labelled diagram how the object is

able to float and spin in the air without any visible support”.

                                          [Refer 7-P5]

Suggestion for modification

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1.      Neutral region should be identified in the diagram given.