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thethe BIGBIG ideaidea
Current can produce magnetism, and magnetism can produce current.
Magnetism
Magnetism is a force that acts at a distance.
Current can produce magnetism.
Magnetism can produce current.
Generators supply electrical energy.
CHAPTER
CHAPTER OUTLINE
21.121.1
21.221.2
21.321.3
21.421.4
CHAPTER RESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
Magnetism is a force that acts at a distance.
SECTION OUTLINESECTION OUTLINE
magnetism
magnet
magnetic pole
magnetic field
magnetic domain
The like poles of two magnets repel each other and the opposite poles attract.
N S
All magnets have a north and south pole.
N S N S S N
21.121.1
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
electromagnetism
Current can produce magnetism.
SECTIONOUTLINESECTIONOUTLINE
electromagnet
A magnet that is produced by electric current is called an electromagnet.
coiliron core
NS
21.221.2
Explore how current and magnetism are related.
SIMULATIONCHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
electromagnetism
Current can produce magnetism.
SECTIONOUTLINESECTIONOUTLINE
electromagnet
A magnet that is produced by electric current is called an electromagnet. Motors use electromagnets to convert electrical energy into the energy of motion.
Motormagnet
electromagnet
21.221.2
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
electromagnetism
Current can produce magnetism.
SECTIONOUTLINESECTIONOUTLINE
electromagnet
A magnet that is produced by electric current is called an electromagnet. Motors use electromagnets to convert electrical energy into the energy of motion.
21.221.2
VISUALIZATIONCLASSZONE.COM
See a motor in motion.
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
Magnetism can produce current.
SECTIONOUTLINESECTIONOUTLINE
generator
direct current
alternating current
transformer
magnet
electromagnet
Generator
Magnetism can be used to produce electric current. In a generator the energy of motion is converted into electrical energy.
21.321.3
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
Generators supply electrical energy.
SECTIONOUTLINESECTIONOUTLINE
watt
electric power
kilowatt
kilowatt-hour
Generators at power plants use large magnets to produce electric current, supplying electrical energy to homes and businesses.
step-down transformers
step-up transformers
shaft
turbine
generator
21.421.4
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
I. Magnetism is a force that acts at a distance.
A. Magnets attract and repel other magnets.
C. Earth is a magnet.
1. Earth’s Magnetic Field
2. Magnetism and the AtmosphereKEY CONCEPTSUMMARYKEY CONCEPTSUMMARY
Magnetism is a force that acts at a distance.
1. Magnetism
2. Magnetic Poles
B. Some materials are magnetic.
magnetism
magnet
magnetic pole
magnetic field
magnetic domain3. Magnetic Fields
1. Inside Magnetic Materials
2. Temporary and Permanent Magnets
21.121.1
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
KEY CONCEPTSUMMARYKEY CONCEPTSUMMARY
Current can produce magnetism.
II. Current can produce magnetism.
A. An electrical current produces a magnetic field.
B. Motors use electromagnets.
1. Motors
2. Uses of Motors
1. Electromagnetism
2. Making an Electromagnet
3. Uses of Electromagnets
electromagnetism
electromagnet
21.221.2
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
III. Magnetism can produce current.
A. Magnets are used to generate an electric current.
1. Generating an Electric Current
2. Direct and Alternating Currents
B. Magnets are used to control voltage.
KEY CONCEPTSUMMARYKEY CONCEPTSUMMARY
Magnetism can produce current.
generator
direct current
alternating current
transformer
21.321.3
CHAPTERRESOURCESCHAPTERRESOURCES
VOCABULARY
KEY CONCEPT CHAPTER HOME
IV. Generators supply electrical energy.
A. Generators provide most of the world’s electrical energy.
KEY CONCEPTSUMMARYKEY CONCEPTSUMMARY
Generators supply electrical energy.
B. Electrical power can be measured.
1. Watts and Kilowatts
2. Calculating Energy Use
1. Generating Electrical Energy
watt
electric power
kilowatt
kilowatt-hour
21.421.4
CHAPTERRESOURCESCHAPTERRESOURCES
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