Page 4 - CBW Magnet & their effects
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14. Breaking a Magnet:
A bar magnet is broken into two pieces. Each piece is then tested by sprinkling iron
filings around it and by suspending it freely with a thread.
a) What do you observe when each broken piece of a magnet is tested with iron
filings?
b) Why do both pieces of a broken magnet still align in the north-south direction
when suspended freely?
c) What would happen if you break a bar magnet into 10 pieces? How many north
poles will you get?
15. Making a Simple Compass:
Ramesh collects a sewing needle, a magnet, a bowl of water, and a small piece of cork
or thermocol. He rubs the needle with a magnet 20–30 times in one direction, inserts it
into the cork, and floats it on still water.
a) Why does he rub the needle with a magnet before placing it in water?
b) What happens to the needle after floating in the water?
c) How does this activity demonstrate that the Earth behaves like a giant magnet?
