Magnets and Magnetic Fields

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Chapter 14

• Magnets and Magnetic Fields

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Chapter 14.1 Notes

• Magnetic pole an area of a magnet where the
  magnetic force appears to be the strongest.
• Magnetic field a region where a magnetic force
  can be detected.
• Compass

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Chapter 14.2 Notes

• The right-hand rule if you imagine holding the
  wire in your hand with your thumb pointing in the
  direction of the positive current, the direction
  your finger would curl is in the direction of the
  magnetic field.

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Solenoid a long, wound coil wire resembles the
magnetic field of a bar magnet.
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• Electromagnet a strong magnet created when an
  iron core is inserted into the center of a
  current-carrying solenoid.

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• Domain a microscopic magnetic region composed of
  a group of atoms whose magnetic fields are
  aligned in a common direction.
• Galvanometer an instrument that measures the
  amount of current in a circuit.

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• Electric motor a device that coverts electrical
  energy to mechanical energy.

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Chapter 14.3 Notes

• Electromagnetic induction the production of a
  current in a conducting circuit by a change in
  the strength, position, or orientation of an
  external magnetic field.

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• Faradays law states that an electric current can
  be produced in a circuit by a changing magnetic
  field.

Faraday wondered Can magnetism produce
electricity? He discovered that a moving magnet
can induce an electric current in a wire.
Michael Faraday
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Dont need to write in notes!!!

• A Faraday cage or Faraday shield is an enclosure
  formed by conducting material, or by a mesh of
  such material. Such an enclosure blocks out
  external static electrical fields. Faraday cages
  are named after physicist Michael Faraday, who
  built one in 1836
• An external static electrical field will cause
  the electrical charges within the conducting
  material to redistribute themselves so as to
  cancel the field's effects in the cage's
  interior. This effect is used, for example, to
  protect electronic equipment from lightning
  strikes and other electrostatic discharges.

Faraday Cage
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• Generator a device that uses electromagnetic
  induction to convert mechanical energy to
  electrical energy.
• Alternating current (AC) an electric current that
  changes direction at regular intervals.

Generator
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• Transformer a device that can change one
  alternating-current voltage to a different
  alternating-current voltage.
• Step-up transformer
• Step-down transformer

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Work Cited

• Earth. May 27, 2008. http//boojum.as.arizona.ed
  u/jill/NS102_2004/Lectures/Lecture3/28_03_Earth_m
  agnetic_field.jpg
• Magnets. May 28, 2008. http//www.physics.sjsu.e
  du/becker/physics51/images/28_01_Bar_magnets.JPG
• Electric Motor. May 28, 2008.
  http//web.ncf.ca/ch865/graphics/DCElectricMotor.j
  peg
• Solenoid. May 28, 2008. http//web.ncf.ca/ch865/
  graphics/Solenoid.jpeg
• Electromagnet. May 28, 2008. http//www.bbc.co.u
  k/schools/ks3bitesize/science/images/sci_dia_79.gi
  f
• Galvanometer. May 28, 2008. http//www.unm.edu/
  physics/demo/html_demo_pages/5k1020.jpg
• Faraday Cage. May 29, 2008. http//sprg.ssl.berk
  eley.edu/clee/images/traveling/boston/CISM_Summer
  _School/Science_Center/faraday_cage1.jpg
• Faraday Picture. May 29, 2008.
  http//itp.nyu.edu/nql3186/electricity/images/far
  aday.gif
• Faraday Cage info. May 29, 2008.
  http//en.wikipedia.org/wiki/Faraday_cage
• Generator. May 29, 2008. http//sol.sci.uop.edu/
  jfalward/physics17/chapter9/generator.jpg
• Electrical Transformer. May 29, 2008.
  http//72.29.25.240/images/electrical-transformers
  .jpg
• Transformer. May 29, 2008. http//72.29.25.240/i
  mages/electrical-transformer-design.jpg