Dispersion(Splitting) of Light through Prism Video Lecture | Science Class 7

light dispersion and refraction through
a prism have you ever noticed that
diamonds sparkle and sunlight ever
wondered why they sparkle and seem to be
giving out different colors just like
oil spilt on any surface showcases
different colors the reason behind this
phenomenon is the refraction of light
before we understand what refraction is
let us conduct this easy and cool
experiment of extracting a rainbow from
white light for this experiment you'll
need a prism white light and a dark room
where the refraction can clearly be seen
procedure take the prism and keep it on
the table ensure that the room is
considerably dark for the light to be
obvious when light travels through the
prism it splits the white light into
seven colors these are violet indigo
blue green yellow orange and red they
appear in the same order just like in
the rainbow observe the light rate
carefully inside the prism notice that
the light ray bends at two different
points one when the light is entering
the prism and another when it leaves the
prism the question is why is the light
being dispersed into the rainbow colors
explanation prisms are made up of glass
the seven different colors coming out of
the prism constitute seven different
wavelengths each color represents a
different wavelength of light
these different wavelengths travel at
different speeds in the glass this is
the main reason for the formation of a
rainbow or spectrum when the light
travels through the prism another point
to be noted here is that the angle of
refraction is different for these colors
as they have different wavelengths when
light touches the surface of the prism
refraction takes place at the boundary
of the prism in example boundary between
air and glass then the white light is
separated into its component colors red
orange yellow green blue indigo violet
refraction is the change in direction of
a wave due to a change medium when these
wavelengths reach the other side of the
prism at different angles refraction
takes place at the surface of the prism
ie at the boundary of the glass and the
prism and the angle of refraction is
greater when they leave the prism this
separation of visible light into its
different colors is known as dispersion
all these colors constitute the spectrum
the angle of refraction which a light
undergoes when it travels from one
medium to another medium is determined
by the refractive index of a given
medium
this is the reason why the diamond
sparkles in broad daylight and makes it
shiny thank you for watching and don't
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