Download Electromagnetic induction Electric currents generate magnetic fields

Electromagnetic induction
Power generation
Power transmission
Transformers
Electric currents generate
magnetic fields
„
demonstration
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Electric currents are pushed
on by magnetic fields
„
demonstration
Electric currents are generated
by magnetic fields
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Electric currents from
magnetic fields
„
Requires changing
magnetic fields!
„
„
demonstration
What’s going on
here?
More coils = more current
„
demonstration
3
Electric motors convert electricity
to mechanical energy
electric motor
Electric generators convert
mechanical energy to electricity
Difference between AC and DC generators
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Transformers!
„
Oops…
Transformers!
„
Used to change
voltage
„
„
Step up
Step down
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Power transmission
„
„
W=V×A
Heat loss ∝ A
How it works
1.
2.
3.
Changing electric
fields in primary
coil generates
magnetic field
Core concentrates
the magnetic field
Magnetic field
induces current in
secondary coil
demonstration
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How it works
„
Voltage change
proportional to
change in number
of coils
„
demonstration
Field induction summary
„
Changing electric
fields → magnetic
fields
„
demonstration
„
Changing magnetic
fields → electric
fields
„
What’s going on?
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