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Chapter 7 S1, Chapter 7 S2, Chapter 7 S3 - Coggle Diagram
Chapter 7 S1
Magnets - Over 2,000 years ago, Greek discovered a mineral that was a natural magnet. This was discovered in the city of Magnesia so the Greeks called this mineral a magnet.
Magnetic Force - When 2 magnets that are alike (positive and positive or negative and negative) are brought together, they repel. When 2 magnets that are opposites (negative and positive) are brought together, they attract.
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A magnetic field is a region of space that surrounds a magnet and exerts a force on another magnet and objects made of magnetic materials.
A magnet is not going to attract all materials. Some magnetic materials are like iron, cobalt, and nickel.
The regions of a magnet that exerts the strongest force are called magnetic poles. All magnets have a north and south poles.
There are atoms on the magnetic materials and these atoms with aligned magnetic poles, they're called magnetic domains.
The Earth's pole and the magnetic poles are reversed. For example, the South pole of the Earth is the north of the magnetic poles.
Chapter 7 S2
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The properties of an electromagnet is that it has a north and south pole and if it is placed in a magnetic field, it will align itself with the magnetic field lines.
The strength of a magnetic field can be increased by adding more turns of the wire to the solenoid or by increasing the current.
A speaker is an electromagnet connected to a flexible cone speaker. The electromagnet changes the electrical energy into mechanical energy and it vibrates the speaker cone which makes it produce sound.
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Chapter 7 S3
Electromagnetic induction - the generation of an electric current by a changing magnetic field is called electromagnetic induction
Direct current or DC is an electric current that i always flowing on one direction through a wire. For example, anything that uses batteries like a remote control.
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Alternative current or AC is an electric current that reverses the direction in a regular pattern. An example of this is anything connected to a wall socket like a microwave.
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Electrical energy is often transmitted through power lines. Electric resistance increases depending on how long the wire is. However, during this some electrical energy might be transformed into thermal energy
Both motor and generators use electromagnets but electric motors convert electrical energy into mechanical energy and generators transform mechanical energy into electrical energy.