Topic 11 - Electromagnetic Induction

11.1 Electromagnetic Induction

Describing Magnetic Fields

Representations of Magnetic Fields

• cannot be seen, so must have standard ways to represent
• arrows on field lines point to the direction a force would act on a magnetic north pole
• distance between field lines indicates the strength of the magnetic field
  • close together is strong, far apart is weak
• analogy: spaghetti
  • distance between a 3d array of spaghetti is the field strength

Relationship between Magnetic Field and Force on Wire

• where is force, is magnetic field strength, is current, and is length
  • see section 5.4

Magnetic Flux

• flux: the total number of field lines measured in Webers ()
  • analogy: amount of spaghetti in a packet
• flux density: the density of field lines ()
• magnetic field strength == magnetic flux density
• magnetic flux: magnetic field strength normal to a surface, multiplied by the area of that surface
• formula for flux:
  • 
• flux linkage: the total number of times any field line crosses any area

Formula Sheet

Checklist

End of Section 11.1

11.2 Power Generation & Transmission

Formula Sheet

Checklist

End of Section 11.2

11.3 Capacitance

Formula Sheet

Checklist

End of Section 11.3