ELECTROMAGNETIC INDUCTION
These are videos for
helping you to understand the information on pages 137 and 138.
Oersted’s
experiment: “All electric currents create magnetic fields”
When the electric current closes, it’s transformed
into a magnet and it creates a magnetic field.
Faraday's experiment: “A
changing magnetic field can produce an electric current”
If we move a magnet in front of an electric cable (or inside a coil of
wire), it generates electricity in the circuit.
Electromagnetic
generators: “Transform mechanical energy (energy from movement)
into electricity”
Dynamo:
Consist of a magnet, inside which there is a coil
ending in two separate semicircular conductors. Dynamos can generate a direct
current.
Alternators:
Consist of a magnet, inside which there is a coil
ending in two rings. Alternators generate alternating currents.
Electric motors: “Transform electric energy into movement” “Motors are
very similar to dynamos, although they work in the opposite way”
It
works on the principles of attraction and repulsion, established by a magnet
and a wire through which electric current flows.
Electromagnet:
Transformers: (page 135)
Transformers consist of two copper coils. If we
apply an alternating voltage to one of the coils, it induces a different voltage
in the other coil.
IT IS OVER
