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Magnets Are More Than Fun
Have you ever played with magnets? Then you know that a magnet will pull some objects toward it. Magnets do this because they make an invisible area called a magnetic field. It is this magnetic field that makes magnets attract objects made from some metals. Metals that magnets will attract are iron, nickel, and cobalt. Magnets will not attract objects made from most other metals, such as gold, silver, or copper.
Bar magnets have two poles, or ends. One end is the north pole. The other end is the south pole. Have you tried putting two bar magnets together? If you put the north end of one magnet close to the south end of the other magnet, the magnets will attract each other. If you put the south poles together or the north poles together, the magnets will repel or push away from each other.
Earth’s Magnetic Field
Earth also makes a magnetic field. Scientists believe this happens because the centre of Earth is made of melted iron and nickel. This makes a big magnet with one end at the North Pole and the other end at the South Pole.
Earth’s magnetic field helps us find directions on Earth. A magnetic compass has a needle. When this needle can move freely, it will point to the North Pole of Earth. Then you can figure out the other directions.
Scientists believe that the poles of Earth have switched in the past. So if you were alive 800 000 years ago, the compasses we use today would have pointed to the South Pole.
Earth’s magnetic field also protects us from solar wind. Solar wind comes from the Sun. It has particles in it that can harm living things on Earth. Earth’s magnetic field protects us by repelling these particles.
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1. What happens when two south poles of a bar magnet are put together?CorrectIncorrect
2. Magnets attract an object made from glass.CorrectIncorrect
3. What is a magnetic field?CorrectIncorrect
4. Fill in the blank using information from the text.
Earth’s magnetic field helps us find on Earth.
5. Why does a needle in a magnetic compass need to move freely?
Great answer!Great answer!
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