Magnetic Field Generator: Toroid

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Magnetic Field Generator Toroid
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Example Force Between Parallel Currents
Four long wires are parallel to each other, their
cross sections forming the corners of a square
with side a 20 cm. A 20 A current exists in
each wire and is out of the page. What is the
force per unit length (magnitude and direction)
on any of wire.
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Magnetic Induction Generating Electricity
1. A current appears only if there is relative
motion.

• Fast motion produces a greater current.

3. Clockwise/counter clockwise current with
north pole move in/out. Opposite with south
pole.
Induced current in secondary coil, if there is
change of current in the primary coil switch or
ac current
Transformer
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Faradays Law of Induction
Electric Flux through area A
Magnetic flux through area A
Amount of electric (magnetic) field passes
through an area A
(Weber, or Wb, or T m2
For uniform B
Faradays Law of Induction An emf is induced in
a loop when the magnetic flux that pass through
the loop is changing. The the loop is
conducting, then a current will flow.
For a loop with N turns
Change B (change current)
Change A
Change angle between them