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(a) Aeroplane hangars / on ships.
(b) It facilitates the task of tightening or loosening screws, seeing that the magnetized screwdriver attracts the screws.
(c) Little force is needed to close the door seeing that it is attracted by magnetism; it is important that a refrigerator should seal tightly.
(d) To remove fine steel splinters from a patient’s eye.
(e) Sound waves are attracted.
(f) Remote-controlled toys.
Let us test our knowledge
(a) Repel; attract.
(b) Those that are attracted by a magnet are magnetic, and those that are not attracted by a magnet are non-magnetic.
(c) Both poles are equally powerful.
(d) North pole to south pole.
(e) Expands.
(f) Copper.
(g) Untrue.
(h) South pole.
(i) North pole.
(j) Test whether it can attract magnetic materials.
(a) A magnet that rotates freely is known as a compass. A compass is used to show direction.
The needle of a compass always comes to rest with one pole – the north or north-seeking pole of the compass - pointing northwards. The other pole of the needle is the south or south-seeking pole.
List two situations in which the use of compasses is necessary:
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(b) Some screwdrivers are magnetised.
What value does this have for the person using it?
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(c) Fridges and some cupboards have magnets in the door.
Why are magnets used in doors?
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(d) Doctors also use powerful magnets.
Can you work out why they do this?
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(e) Telephones and loudspeakers contain magnets.
What is the purpose of having magnets in such instruments and appliances?
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(f) Some toys have magnets.
Which toys that you know have magnets and why do they have them?
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