Eletromagnétic field representation

[PrimoCosta]

Hello so my doubt is when i are teaching about eletromagnétic filds the frist time a do a representatios is of a full field i Draw the two waves, ume perpendicular to another, and istill i know that's not the best representatios because i should have to rolate the wave while a draw.

Later in the same Class i stop drawing the full eletromagnétic field and it's became a simple wave, but iknow that's when i do this some of the informations is lost and i never could explain to the studentes why i do this, i just do and i know i cam from the textsbooks. So here's my doubt who do i explain to them that's is reliable do this change in the way a represents the eletromagnétic field, i wold really apreciate if some on has a demostration to this ou a textbook to recomendate.

Sorry for my bad english I'm not native in english.

 

[Dale]

Summary: diferences between two kinds of representation.

who do i explain to them that's is reliable do this change in the way a represents the eletromagnétic field

In the far field you have $\vec S=\vec E \times \vec B$ so if you show $\vec E$ and you know $\vec S$ then $\vec B$ is uniquely determined and doesn’t need to be drawn.

 

[PrimoCosta]

Thank you it really helps i don't like entering in class with half explanation.