EM 03 -

SAFARI GUIDE: Ian

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OPENING QUESTION:

Let's take another hack at our magnet-in-a-metal-tube connundrum

OBJECTIVES: I will be able to explain how a changing B field results in a changing E field during today's class

WORDS/FORMULAE FOR TODAY

TERMS

  • Inductance
  • Magnetic Flux (ΦB)
  • Magnetic Field (B): A vector value
  • Magnetic Force (FB): Also a vector

CONSTANTS:

 

UNITS:

      • Tesla = T defined as 1 N/C(m/s)

FORMULAE:

      • ε = -dΦB/dt = -Bℓv = ∫E ∙ ds
      • ΦB = ∫B ∙ dA
      • B ds = μoI: Ampere's Law
      • dB = oI/4π)(ds x )/r2 (note here is the unit vector like i, j, or k. Biot-Savart Law
      • FB = ∫I ds x B NOTE: AP Version is: FB = ∫I d x B
      • v = E/B
      • FB = qv x B (vector value)
      • FB = qvBsinθ (FB magnitude of only)
      • FB = IL x B

CALENDAR:

WORK O' THE DAY:

Take a gander at the following graphic:

Now please do THIS (I just happen to have some 11" x 17" paper for just this occasion)

Please create an articulately designed 8 panel cartoon/sketch that addresses the following:

What is a charge?

How is a charge related to electric field?

How is electric field related to electric potential?

How is electric potential related to electrical current?

How is electric current related to magnetic field?

How is magnetic field related to magentic force?

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NOW let's take another swing at explaining our magnetic in a tube

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Finally -- with our new knowledge of induced E fields, we have yet ANOTHER equation for EMFs:

∫E ∙ ds

By the by, just HOW do you suppose our equation sheet shows that particular formula?

∫E ∙ dℓ

 

STUDY:

COURSEWORK (begining on page 963): 31.39 and 31.40