Magnets and Electricity
Learner Expectations
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Content Standard: 14.0 Energy |
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The student will investigate energy and
its uses. |
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Learning Expectations: |
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14.1 Know that energy exists in many
forms. |
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14.2 Recognize the characteristics of
light energy and sound energy. |
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14.3 Recognize the properties and uses
of magnets. |
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14.4 Recognize the basic concept of
electricity. |
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In this activity you will:
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Learn about magnetism and electricity. |
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Write a paragraph using three facts
about magnetism and three facts about electricity. |
What is magnetism?
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Magnetism is the force of attraction
between magnets and magnetic objects. |
Characteristics of
magnets
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Every magnet has two poles (North and
South) |
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Every magnet has a magnetic field
around it. |
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The magnetic field is lines of force
running from the north-seeking pole to the south-seeking pole of the magnet |
What do you know of that
has a North and South Pole?
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If you answered The Earth you were
right! |
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The Earth is one giant magnet. It has
two magnetic poles and is surrounded by a magnetic field. |
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This magnetic field is what causes the
needle of a compass to point in different directions and causes the poles of
a magnet to point either north or south. |
Do opposites attract?
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Yes! |
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The north and south seeking poles of
two magnets attract each other- magnetic force pulls them together. |
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But if you try to bring two of the same
poles (two norths or two souths) together they will repel each other. |
Magnets and electricity
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Magnets are used to generate, or
produce, electricity. |
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Spinning a coil of wire inside a
magnetic field produces an electric force between the ends of the coil. |
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In a similar way, an electric current
produces a magnetic field around it. |
Electromagnet
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A temporary magnet made by passing
electric current through a wire coiled around an iron bar. |
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A junkyard is one place to see an
electromagnet in action. A crane holding a huge electromagnet can be used to
pick up scrap metal when current flows through it. When the crane operator
wants to drop the scrap, he or she will simply shut off the current to the
electromagnet. |
Ten Facts about Magnets
(from the book Driving Force)
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1. North poles point north, south poles
point south. |
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2. Like poles repel, unlike poles
attract. |
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3. Magnetic forces attract only
magnetic materials. |
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4. Magnetic forces act at a distance. |
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5. While magnetized, temporary magnets
act like permanent magnets. |
"6."
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6. A coil of wire with an electric
current flowing through it becomes a magnet. |
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7. Putting iron inside a
current-carrying coil increases the strength of the electromagnet. |
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8. A changing magnetic field induces an
electric current in a conductor. |
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9. A charged particle experiences no
magnetic force when moving parallel to a magnetic field, but when it is
moving perpendicular to the field it experiences a force perpendicular to
both the field and the direction of motion. |
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"10."
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10. A current-carrying wire in a
perpendicular magnetic field experiences a force in a direction perpendicular
to both the wire and the field |
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Writing Activity
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Write a paragraph about magnetism and
electricity including three facts about each that you learned during this
presentation. |
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