The Cause of Magnetism

1
SPI 080712.2 Electromagnetism
Notes
Science
The Cause of Magnetism

• Atoms and Domains
• In materials such as iron, nickel, and cobalt,
  groups of atoms are
• in areas called domains.
• The north and south poles in a domain line up and
  make a
• strong magnetic field.

2
SPI 080712.2 Electromagnetism
Notes
Science

• Electromagnetism
• Is the interaction between electricity and
  magnetism.
• Electric current produces a magnetic field.
• An electromagnet consists of a solenoid wrapped
  around an iron core.
• Turning Electromagnets On and Off
• Unlike permanent magnets, electromagnets can be
  turned on and off as needed.

• Electromagnetic Strength
• You can adjust the strength of an electromagnet
  two ways
• 1) Use more electrical current
• 2) Use more coils

3
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• Found in electrical motors and switches
• To lift objects
• Example Junkyard crane-magnets
• Example Maglev trains
• To propel objects
• Example Railguns as weapons
• Example Railguns as launch platforms
• To look inside of people
• Example Magnetic Resonance Imaging (MRI)

4
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To lift objects
• Example Junkyard crane-magnets
• Video Clip Scrapyard Electromagnet In Action

5
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To lift objects
• Example Maglev trains (magnetic
  leviation-reduces friction)
• Video Clip How Maglev Trains Work

6
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To propel objects
• Example Railguns as weapons
• Video Clip U.S. Navy Railgun

7
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To propel objects
• Example Railguns as launch platforms (for
  space)

8
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To propel objects
• Example Railguns as launch platforms (for
  aircraft)
• Video Clip Aircraft Carrier Launcher

9
SPI 080712.2 Electromagnetism
Notes
Science

• How do we use electromagnets?
• To look inside of people
• Example Magnetic Resonance Imaging (MRI)
• Video Clip MRI Magnetic Field Strength