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3.2.3.       Faraday’s Law   <CJ chap 22.1-22.6  >

3.2.3.1. Discussion

3.2.3.1.1.     Faraday’s discovery of induction allows for the  creation of a voltage by moving a loop in a B field

3.2.3.1.1.1. Either the flux can change due to the motion or orientation of the wire or loop or

3.2.3.1.1.2. The flux can change due to a changing magnetic field or even the motion of the source magnet

3.2.3.1.2.      

3.2.3.2. Mathematical

3.2.3.2.1.     Faraday’s law of induction: V = - DF_B/Dt  and F_B  = B  A the magnetic flux through an open surface

3.2.3.2.2.     Lenz’s law: the induced EMF will create a magnetic flux to oppose the change in magnetic flux

3.2.3.2.3.     EMF from the motion of a conductor in a B field:  V =  -B s v  for a conductor of length s moving at v

3.2.3.3. Advanced

3.2.3.3.1.     Faradays law V = - dF_B/dt  and F_B = B ds the magnetic flux through an open surface

3.2.3.3.2.     But V (induced emf) around a closed circuit is  V =  E ds  =  - d/dt  B ds