Reflection, refraction of the light
moving from one medium to another medium
in different refractive indexes.
so let’s
learn about some of these concepts.
In
physics we have a light source that I can turn on turn it off. and
I have two materials
this material is air and this material
is again air let’s say if I shine a
light then nothing happens light just
transmits through this medium the medium
is same everywhere this is what is
happening in our air so although we have
a different layers of air and molecules
in our atmosphere this doesn’t usually
happens but so air to air light just
goes transmits nothing happens so let’s
say if I change the material to with
water and I shine the light now you can
see if I shine a light on the surface of
a water from air then some of the light
is reflected back and most of the light
is transmitted and transmitted it as you
can see it is not going in the same
direction
Eadie’s was in the first medium in air
it’s changing its path so the light is
bending if I draw a line let’s say if I
draw a perpendicular line on a point
where I have an incident ray this we
call it array and reflected ray and
transmitted ray if I draw a line at that
point that that’s what we will call it a
normal so this black line
the dashed black line is a normal so as
you can see from a normal as it hits the
boundary the light bends so we can
measure how much it bends by using a
scale so so we can see from 0 to 30 and
then 4045 I have an incident light
making an angle of 45 degrees 45 degrees
with a normal where you can see their
reflected is going up with the same
angle you can see the 45 degrees so when
a light is incident on the material the
reflected light goes out with the same
angle with the normal this is the
property of a light so light travels in
a straight path when it is when it hits
the boundary it will go back with a semi
angle but when you look at the light
which is transmitted inside the medium
you can see the light is bended towards
the normal and this is making an angle
which is less than you can see it’s it’s
it’s at 30 30 degrees so if I draw an
angle here between normal and right lay
I see this is a little bit greater than
30 degrees but less than of course 45
degrees so my angle of reflection
refraction is smaller than the angle of
incident so this is my angle of incident
and this is my angle of refraction now
what about the light how much light is
reflected and how much light is
transmitted here if I want to measure
let’s measure the intensity as you can
see here the intensity of a light here
is 100% so what happens light let’s
check it here the intensity of light is
5.2 9% here what about the rest of the
light the rest of light is transmitted
here so 94.7 1
% so when you see a water surface and
you see a light on it so the most of the
light is observed inside the water and a
very small amount of light is reflected
back so that’s why I do in summers the
water
alack slivers are mostly lacks gets heat
up so it gets warmer because Lord of the
light is observed inside the water now
let’s check it another material let’s
say if I change my material if I change
my material the second material this
material from water to glass what
happens so when I change my material
from water to glass I can see the light
is more bent towards the normal and if I
want to measure the intensity here again
100% light I have and the reflected
light is nine point one line so the
reflection increases while we have the
absorption is ninety percent so the
reflection is nine point one percent so
the light is bending towards normal I
can this is a ray diagram I can draw a
wave diagram also so I can just turn on
the whale well let’s keep real for now