Magnetic Field in polarisation ?

[mkbh_10]

Why is only electric field considered when we discuss the phenomenon of polarisation ? What about the magnetic field ?

 

[lanedance]

i assume you are talking about light?

magnetic field as always perp to the electric, so will be polarised in the same manner but rotated 90deg

 

[mkbh_10]

i think its because the direction of magnetic field is helical whereas the electric field is straight .

 

[lanedance]

ahhh... no the magnetic polarisation will be the same as the electric

ie linearly polarised light has both linearly polarised eletric & magnetic fields, both at 90deg to teh directino of propogation & to each other

similarly cicularly polarised light has both cicularly polarised eletric & magnetic fields, still both at 90deg to the direction of propogation & to each other

try finding the equation for a plane wave and check it out

 

[mkbh_10]

I am not saying that the polarised light will not have magnetic field , it will have it but genreally in polarisation we don't talk abt the mag field & i think the reason i gave must be it .

 

[lanedance]

for linearly polarised light the magnetic field will be lineraly polarised not helical, so that reason is not correct

have a look here
http://en.wikipedia.org/wiki/Electromagnetic_radiation

if you want to get into the philosophical side of things then we probably usually talk about electric field as the relative strength is B = E/c. So in terms of interacting with things the electric part is probably more significant.