electromagnetics basic

[amodism]

While electromagnetic wave can pass through a perfect dielectric ( i.e. an insulator), current/voltage cannot. still in a waveguide, both wave and current exist simultaneously. why?

 

[jiripolivka]

A waveguide is a device that guides the elmag wave. The process is done by inducing currents in conductors or moving charges in dielectrics.
Without objects around, the elmag wave propagates in a free space, free of objects.

 

[Twisha]

Hi

The EM Wave propagation can be explained as follows:
1) A charge in motion causes an electric field.
2) This electric field in turn produces a magnetic field
3) The magnetic field produces an electric field again and this process continues.
While a charge is needed to generate an electric field, it is not necessary for its propagation. An EM Wave has both electric and magnetic fields mutually perpendicular to each other. However, EM waves are do not have any charge. Charge is needed just for initiating a field like the voltage applied to the antenna. Upon application of voltage, electric and magnetic fields are produced which propagate without any charge. The propagation of EM waves depends on the properties of the waveguide or the medium of propagation and not the source of excitation.

Regards
Twisha

 

[jiripolivka]

I you read so much, why you ask for an explanation?