Transformers
Used to change voltage of alternating currents
The same amount of electric power can be delivered through wires at low voltage and high current as at high voltage and low current
Using low electrical current for electric energy transportation is more efficient: loss of electric energy in the wires smaller
Transformer: changes the voltage!
Transformers made up by two coils on one iron core
first coil: primary coil (N1 turns), connected to a source of alternating current (V1)
second coil: secondary coil (N2 turns), produces an alternating voltage (V2)
principle (the alternating magnetic field produced by the primary coil, induces an alternating voltage in the secondary coil)