Applications on total reflection - Ray, Optics & Optical Instruments Video

so I today we've talked about
supplications and the total reflection
of what
so the first application that we have is
the optical fiber so optical fibers are
ten cylindrical thread shaped fibers
through which light is directed to move
in um straight lines so they are they of
the optical fibers to force the light
not to move in a straight line to move
in the half of the optical fiber because
we know that light moves in straight
lines and in some cases we want to lead
light to some place where if it moves in
straight lines it will not reach
distance so optical fibers are widely
used in medicine like in endoscope which
is used in diagnosis and it's also used
with lasers because lasers are capable
of carrying millions of electrical
charges through the electrode fibers
which are characterized by the
characteristics of the optical fibers
and we'll talk about the lasers later so
what happens is when the incident light
Falls with an angle higher than the
critical angle for example at this it
refracts inside the optical fiber then
mr. fraction is filled by multiple
reflections inside the optical fiber and
this moves through the optical fiber to
it reaches the other end and then light
emerges from the other oh so this is how
lights move through the optical fibers
so even if the optical fiber is bent the
light will move through the curve of the
optical fiber and not in a straight line
the second application is the
reflecting prefer the refractive index
of class is 1.5 so the critical angle
between glass and air is about 42
degrees so the prism which we use in
here is the reflecting prism it's a
right angle prism and this ISO CIL's
because each of the other two angles or
45 degrees sceptic prism can reflect
light by 90 degrees for 180 degrees for
example light goes from this side we
will see that light reflects this way
this is the normal and so let's post by
this angle so this is the right angle
this would be also 45 degrees so the
angle of reflection will also equal 45
degrees so the letter e will go in this
path this angle accordingly will be 90
degrees so here life is afflicted by 90
degrees in the other prism if what goes
through the hypotenuse of the triangle
so it holds this angle then it's
reflected then it pulls in this angle
this is how the light is reflected five
hundred eighty degrees through using the
right angle prism so here the right
angle is in this place and here the
right angle is on this place these
prisms have an advantage over the metal
surfaces that reflect light because the
efficiency of these prisons is about 100
percent while the metals that reflect
the light absorb some man to fly through
the crust
reflection so there is a loss of life
also the metals that reflect light have
an attack lustre and so they are
subjected to corrosion and this
decreases the capability of these metals
to reflect the light and finally as
there is also some little amount of loss
of light inside the prisons they may be
lying from the inside by substance
called cryolite which is formed from
aluminum chloride and magnesium chloride
because they have a refractive index
less than glass so this even prevents
any loss of reflection of light and so
the efficiency of the prism becomes
nearly 100% the reflective prisms can be
used in binoculars or in periscopes in
submarines so that people can see
outside the submarine or see what's
found in the surface of the sea so the
last thing that we are going to talk
about is Mirage so if somebody is in
desert and he sees in the sand the shiny
spots where the reflection of the object
surrounded is found so you think that
this is a water pond
well there's nothing so this is what
happens so the sun's heat heats up the
sand because the Santa pups heat and so
it becomes very warm so it heats up the
air layer adjacent to the sand this
leads to decreasing the density of the
air in the layer adjacent to the sand so
the density of this layer decreases and
it becomes less than the density of the
air in the upper layer
then when the light pulls on the palm
tree and then it's reflected so that you
can be able to see the palm tree what
happens is now the large ray shall move
from up to down due to the difference in
height so when it goes from the palm
tree downwards the angle of incidence on
the air becomes more than the critical
angle and at that point because the
density of this error is less than
density of the air above the light ray
deviates and when it reaches the point
where the critical angle is less than
the angle of incidence it takes another
path and it makes a curve that goes
upwards like that so when you receive
the light you think that it's going to
you from downwards while it's actually
coming from upwards but the light ray
deviated due to the difference in
density between the air addition to the
sand and the air in the upper plane so
this is how a mirage takes place this is
it for today until the next time and
thank you for watching and see