Unit 2 Magnetism How does the movement of charges influence a magnetic field Sphys 5'1 d

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Unit 2 MagnetismHow does the movement of charges
influence a magnetic field?Sphys 5.1 d
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Permanent Magnets
Magnetic Properties

• A magnet is a material that has the ability to
  attract and repel other magnetic materials
• Permanent magnet
• Material that keeps its magnetic properties, even
  when it is not close to other magnetsalways a
  magnet!

• Poles (north and south)
• Even if you chop them in half, they retain their
  magnetic properties
• Magnets exert magnetic forces on each other
• The forces between magnets depend on the
  alignment of the poles
• Like poles repel
• Opposite poles attract

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Magnetic Field

• Developed to describe how a magnet exerts
  magnetic force
• Every magnet creates an energy field in the space
  around it
• The field exerts forces on any other magnet that
  is within its range

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Permanent magnets Electromagnets

• Creating electromagnets
• Send an electrical current through a coil of wire
  wrapped around some iron
• How do you strengthen an electromagnet?
• Increase Current Current controls the strength
  of an electromagnetmore current, stronger magnet
• Increase the size of the core
• Increase the number of coils around the core
• UsesMagnetically levitated trains (monorails)
  and roller coasters

• Electric currents cause all magnetism
• Electrons move creating small loops of current
• Iron attracts magnets because its atoms are free
  to rotate and align their north south poles

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Force Induction

• Electromagnetic force
• An electrical and magnetic force between
  electrical charges
• Electromagnetic induction
• A current is created in a wire by a moving magnet
• The reverse is also true
• Because a moving magnet induces electrical
  current to flow

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Electric Motor
Generators

• Generators-make AC current using a coil of wire
  rotating in a magnetic field.
• This produces a current.
• Wire rotated by outside forces.

• Uses a permanent and an electromagnet.
• The electromagnet rotates in the permanent
  magnets magnetic field
• Creates current.