magnetic fields

• magnetic field lines - the region around a magnet where a force acts on another magnet or on a magnetic material (eg iron cobalt steel nickel)

  • used to represent strength (spacing) & direction (arrows) of magnetic field
  • closer field lines = strong
  • they always go from north to south and never touch or cross other field lines
  • field is strongest at poles (field lines closest tgt)
  • weaker as the distance from the magnet increases (field lines further apart)
• label

  A) n

  B) s

  C) >

  D) >

  E) <

  F) <

  
• label

  A) pushes

  B) uniform

  C) no

  
• label

  A) v

  B) >

  C) <

  D) >

  E) <

  F) ^

  G) <

  H) <

  I) >

  J) <

  K) <

  L) <

  M) >

  N) v

  O) ^

  
• representing magnetic fields

  • Two bar magnets can be used to produce a uniform magnetic field
  • produced in the gaps btwn opposite poles Note: Outside that gap, the field will not be uniform
  • same strength, direction at all points: equal spacing & arrow on each magnetic field line (n to s)
  • same distance apart btwn gaps: field strength same at every point between the poles
  • determined by using plotting compasses pointing from north to south or by using iron filings
  • direction of the field line at a point is the same as the direction of the force a north pole would experience at that point