Download An electromagnetic wave in vacuum has the electric and magnetic

An electromagnetic wave in vacuum has the electric and magnetic fields E⃗ and B⃗, which
are always perpendicular to each other. The direction of polarization is given by X⃗ and
that of wave propagation by k⃗. Then :
(a) X⃗||B⃗and k⃗ || B⃗ E⃗
(c) X⃗ || B⃗ and k⃗ || E⃗ B⃗
(b) X⃗ || E⃗ and k⃗ || E⃗ B⃗
(d) X⃗ || E⃗ and k⃗ || B⃗ E⃗
In an electromagnetic wave electrical and magnetic fields are perpendicular to
each other.
Wave propagates in a direction perpendicular to both electric and magnetic filed
as given by E⃗ B⃗ .
Direction of polarization is perpendicular to direction of oscillation.
Optical phenomena are due to electric field.
In the polarization of light, it is the electrical field that gets polarized.
Therefore direction of polarization must be perpendicular to electric field and
parallel to magnetic field.
Read the problem once more: … The direction of polarization is given by X⃗ and
that of wave propagation by k⃗.
Here, The direction of polarization = X⃗ . This must be perpendicular to
electric field and parallel to magnetic field.
X⃗ || B⃗
The direction of wave propagation = k⃗. This must be perpendicular to electric
and magnetic field.
k⃗. = E⃗ B⃗ .
Therefore option ( c ) s correct.