Student Activities

Place some iron filings on a paper. Place a bar magnet horizontally in the filings and turn it over a few times. Now lift the magnet. What do you see? Which part of the magnet has more iron filings sticking to it? _____________

Which part of the magnet has almost no filings sticking to it? _______________

The parts of the magnet those attract the largest amount of iron filings are called as its poles. The attractive force of the magnet is very large near the two ends. These two ends are called its poles.

If you have a horseshoe magnet, or any other type of magnet at home, find the position of its poles by this experiment.

In experiments with magnets you will need to use iron filings again and again. You can do this by placing a magnet in a pile of sand and turning it around in the sand. The small pieces of iron present in the sand will stick to the magnet. If you cannot find sand you can look for iron pieces in clayey soil as well.

If you don’t have iron filings, you can collect small pieces of iron and they will serve the purpose as well.

Turn the magnet gently and let it come to stop again. Repeat it three or four times.

Does the bar magnet stop in the same direction each time?

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In which direction does the magnet stop every time ? ---------------------------------------

This is roughly the north-south direction. The end of the magnet that points to the north is called the North Pole. The end that points to the south is called the South Pole.

A freely suspended magnet always comes to rest in north-south direction.

The directive property of magnets has been used for centuries to find directions. Around 800 years ago, the Chinese discovered that a suspended lode stone stops in the north-south direction. Chinese used these lode stones to find directions.

The navigators of that country used to keep a piece of lode stone suspended in their boats and during a storm or mist, they used the lode stone to locate directions.

Take two similar magnets, place them in four different ways as shown in Figure.

What do you observe? When do the magnets attract each other?

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When do the magnets repel each other?

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Unlike poles (S-N, N-S) attract each other. Like Poles (N-N, S-S) repel each other.

Activity 2: LET US MAKE MAGNETS

Take a nail / a piece of Iron and place it on a table. Now take a bar magnet and place one of its poles near one edge of the nail / piece of Iron and rub from one end to another end without changing the direction of the pole of the magnet. Repeat the process for 30 to 40 times.

Bring a pin or some iron filings near the nail / piece of Iron to check whether it has become a magnet. Does the nail/ piece of iron attract the pin / iron filings? If not, continue the same process for some more time.

Do magnets lose their properties ? When?

Magnets lose their properties if they are heated or dropped from a height or hit with a hammer.

Magnets lose their properties when they are placed near Cellphone, Computer, DVDs. These objects will also get affected by magnetic field.

Activity 3: Make your own magnetic compass

Insert the magnetized needle, that you made in the activity 2, in to two styrofoam balls (Thermocol balls) and place the needle in bowl of water. Test whether the floating needle is always turned in rest on north - south direction.

Note: If you don't have styrofoam balls you can use dry leaf or a cork piece.