now let us study the most popular and useful
theory, for explanation of understanding of
light, that is maxwell’selectro magnetic
theory. in 18 73, the theory was given by,
maxwell, and it was said that, light energy,
is a wave, which is, electro magnetic in nature,
in which, electric field vector and magnetic
field vectors, oscillates simultaneously,
in planes, perpendicular to direction of,
propagation of light. here this particular
situation explains how the light propagates
when the light is emitted, electric field
and magnetic field vectors oscillate, in the
direction perpendicular to the propagation
direction as well as here, e vector and b
vector are perpendicular to each other. if
we just plot the locus of the electric and
magnetic field vector, such kind of envelope
is obtained, which gives us the way, how electro
magnetic wave propagates, and it travels in
the direction perpendicular to both the planes,
with speed of light c. and here, e vector
and b vector are related as, here e is given
as c b, where c is the speed of light. and
in case of light mainly e vector is called,
light vector, because for human eye, and most
of the phenomenon associated with light, electric
field vector is responsible for, sensation
and other characteristics of light. magnetic
field is also useful for propagation of energy,
in the direction of propagation but, this
electric field vector which is responsible
for most of the characteristics of light,
including the vision sensation in, human eye.
so electric field vector is generally termed
as light vector. and theory of electro magnetic
waves, which are explained for light propagation,
are the most important and useful theories
which explain majority of, phenomenon associated
with light but not all phenomenon like photoelectric
effect, and some other phenomenon associated
to, particle nature of light are not explained
with the help of electro magnetic theory but
in most of the cases, this is a useful theory.
And, now onward we’ll study about some important
phenomena of, light in the coming sections.
