# Shared Flashcard Set

## Details

8
Physics
11/14/2008

Term
Definition
 a changing magnetic field from a changing current induces an emf
Term
 Magnetic Flux, ΦB (4)
Definition
 the induced emf in a wire loop is proportional to the rate of change of magnetic flux through the loopΦB = B┴A=BAcosθWeber, 1 Wb=1 T·m2proportional to total number of lines passing through  the loop
Term
Definition
 &=-N ΔΦB/Δt = Blva changing magnetic flux, ΔΦB induces and electric field
Term
 Lenz's Law (2)
Definition
 a current produced by an induced emf moves in a direction so that its magnetic field opposes the original change in flux used to determing direction of conventional electric current induced in a loop due to a change in ΦB
Term
 Electric generator
Definition
 opposite of a motor; transforms mechanical energy into electrical energy
Term
 Transformer (3)
Definition
 consists of 2 coils either interwoven or linked by an iron core; a changing emf in one induces an emf in the othervoltage ≈ turns (N) ≈ 1/current Vsec/Vpri=Nsec/Npri=Ipri/Iseconly work if the current is changing (AC)
Term
 Lorentz's Force Law (electron & magnetic)
Definition
 Felectron = evBFB = qv x B e=electron charge=1.6x10-19C
Term
 Induced EMF
Definition
 when a conductor moves through a uniform magnetic field
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