Chapter 25 Electromagnetic Induction
A moving or changing magnetic field causes an electric field (which causes a current in a circuit).
EMF = BLv (sinθ)
http://www.walter­fendt.de/ph11e/lorentzforce.htm
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How a generator works:
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Lenz's Law An induced current will flow in such a direction as to oppose by its magnetic field the change which produced it.
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Transformers
Used to change alternating current of one voltage to alternating current of a different voltage.
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Equations for Transformers:
Vp/Vs = Np/Ns
VpIp = VsIs
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Np = number of turns in primary
Ns = number of turns in secondary
Vp = primary voltage
Vs = secondary voltage
Ip = primary current
Is = secondary current
Important to note: A STATIC magnetic field does not cause current. Only a moving/changing magnetic field will cause a current.
http://micro.magnet.fsu.edu/electromag/java/compass/index.html
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