Magnetism – Session 2

Session on 24/12/2011

The objective of the activity conducted in the last session was not complete. So, the first task was to complete that. The learning objectives for this session –

• Activity objective – The material the object is made of determines if it will be pulled by the magnet.
• Magnet can exert push and pull [We covered only pull in the last session]
• When magnet pulls an object towards itself, the pull is known as attraction
• When magnet pushes an object away from itself, the push is known as repulsion
• Magnet attracts some metals like iron, steel.
• Misconception to be checked for – Magnets attract all metals; Magnets attract only silver coloured metals

The class began with a re-cap of what was learnt in the earlier session -push, pull, magnet pulls some objects and does not pull some objects.

The class was divided into groups of 2. One student in each group was blind folded, and had to identify if the object kept in front of them will get pulled by the magnet. They were not supposed to touch/feel the object. All they could do is to ask 5 questions about the object to their partner and find based on the answers. The partner can see the object.

Group 1 – Object – paper clip

Questions asked –

1. What is the color? Silver

2. What is the shape? Triangle

3. Is it a solid? Yes

Then the student did not know what more questions he could ask. So, I had to help. I asked a question on his behalf – what is the object made of ? Iron. Immediately the blindfolded boy was able to identify that it would get pulled by the magnet.

Similar rounds happened for the other groups and slowly ‘what is the object made of?’ became the first question.

So, they understood that one should know the material with which the object is made to find if it will be pulled by the magnet.

Now, I introduced the term magnetic and non-magnetic materials.

After this, I gave some magnets to each student and just watched them play with it. They were free to do anything with it. As we were sitting on a terrace, they took it to an iron rod and experienced the pull (no one asked me why the iron rod was not moving towards the magnet unlike the paper clip or nail).

One girl, put it on her hair clip and found that it was getting pulled. The other one put it on her gold ear ring and said it was not getting pulled. Then I used my toe ring (made of silver; silver in color). This was primarily to remove any misconceptions they had that all silver objects would get pulled by the magnet.

Then one girl came by to say that only iron gets pulled, no other metals will get pulled. At this point, I introduced names of 2 more metals which get pulled – cobalt, nickel. Though they were not aware of these, I thought it would be good to just make them aware. They were familiar with aluminium and they saw that aluminium does not get pulled.

2 possible misconceptions were checked for -Magnets attract all metals; Magnets attract only silver coloured metals.

It was time to show them that magnets do exert push too. For this, I gave each student 2 magnets and they had to just being them close to each other to experience the pull. Some had pairs of bar magnets and others disc magnet. On turning the side of the disk magnet, they could experience the push. One student was so happy, she came by to say that the push was because there is air between the 2 magnets 🙂 A possible distractor for one of the questions.

Now, that they experience push and pull, it was time to introduce the terms attraction and repulsion. To most students, the terms were new, but one confused attraction with ‘attentive’. She pointed at a boy who was not attentive in the class and said, he is not attractive 🙂

As we completed the planed objectives, I just let them play with the magnets and some paper clips, bell pins, nails, balls, coins. They were trying to hang the paper clips one below the other using the magnet. They could do only 5 clips with a magnet. I asked them what they would do to get more clips using the magnet. When there was no answer, I put the 2 magnets together and gave them to try again. Now, they were able to pull more clips, when asked for the reason, they said it is because the magnet now has more weight and I was totally stumped!! I did not even expect that answer in my dreams and had no way to prove them that weight was not the reason and it was the power of the magnet.

Finally one boy blurted the word “power” and it came as a saviour!!

Next session – 3rd Jan.