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2. ELECTROMAGNETICS FIELDS

2.1 GENERALS

The e.m wave. born from the coexistence of two sizes, electrical field and magnetic field permanently variables and confused between them of 90°, it propagates in the empty space at the light speed.
When the e.m wave meets a circuit induces currents and tensions dependent from the source and the dimensions and trend of the circuit, if these induced activity signals exceed the circuit sensitivity level it derives a malfunction.
To reduces distances from the source the magnetics field act independent and in this condition, named "nearby field", and can have a due disturb and the magnetic and/or electronic pairing independent.
Nearby to the source it is a "induction field" its characteristics are tied to the source; the pairing will be the magnetic type if the source is to the high current, electric type if it is to the high tension.
The condition of the nearby field ends to the distance of the even wave source at d = l/2p; after that it is entered in the "distant field" area where the e.m. wave it's like a plain wave and it is showed through the "radiation field".
When meets an obstacle the e.m. wave suffer a reflection in the impact with the surface and then a energy loss for the permeability in the cross the obstacle, the part that crossed the obstacle follows its way after the second deviation.
The entity of the absorb and reflected part in tied to the electrics and magnetics characteristics of the obstacle beyond its dimensions depends also from the source obstacle.
The e.m. wave is propagated suffering an attention proportional to the pass distance, in particular: The radiate field is reduced by a proportional factor at 1/r. The electric induction field is reduced by a proportional factor at 1/r². The magnetic induction field is reduced by a proportional factor at 1/r³.