Like this presentation? Why not share!

# Dispersion of light

## on Jan 05, 2012

• 15,183 views

### Views

Total Views
15,183
Views on SlideShare
15,182
Embed Views
1

Likes
1
496
7

### 1 Embed1

 http://rushika.siliconleaf.com 1

### Report content

• Comment goes here.
Are you sure you want to
• Super marvellous
Are you sure you want to
• good
Are you sure you want to
• a very good presentation....
Are you sure you want to
• Good presentation
Are you sure you want to
• it's very good
Are you sure you want to

## Dispersion of lightPresentation Transcript

• Dispersion of Light Projectee - Nishtha Pathak Class - 10 th ‘B’
• What is Dispersion?
• The splitting up of white light into its seven constituent
• colours on passing through a transparent medium (like
• glass prism) is called dispersion of light.
• Cause of Dispersion
• The dispersion of white light occurs because colours of
• white light travel at different speeds through the glass
• prism. The amount of refraction depends on the speed
• of coloured light in glass. Now, since the different
• colours travel at different speeds, they are refracted by
• different angles on passing through the glass prism.
• So, when white light consisting of seven colours falls
• on a glass prism, each colour in it is refracted by a
• different angle, with a the result that seven colours
• spread out to form a spectrum.
• Spectrum
• The band of seven colours formed on a white screen,
• when a beam of white light is passed through a glass
• prism, is called spectrum of white light. The seven
• colours of the spectrum are: Violet, Indigo, Blue,
• Green, Yellow, Orange, and Red. It can be denoted by
• the word VIBGYOR.
• Newton’s Experiment
• Newton performed an experiment to show that white
• light consist of colours. A white light ray is passed
• through a prism to split it into the colours of the
• spectrum. The different coloured light is allowed to
• pass through an identical prism kept in inverted
• position. The light emerging out of second prism was
• found to be white indicating that the light ray consist of
• colours.
•
• Rainbow
• A rainbow is a natural spectrum appearing in the sky
• after a rain shower. It is caused by dispersion of
• sunlight by tiny water droplets present in the
• atmosphere. A rainbow is always formed in a direction
• opposite to that of the Sun. The water droplets acts
• like a small prism. They refract and disperse the
• incident sunlight, then reflect it internally, and finally
• refract it again when it comes out of the raindrop. Due
• to the dispersion of light and internal reflection,
• different colours reach the observer’s eye.
•
•
• Lets Find Out More Facts
• What is the range of visible light?
• Range of visible light – 0.4 microns to 0.7 microns.
• Visible light has a large number of radiations having wavelengths ranging from 0.4 microns to 0.7 microns. That is, red light has a large wavelength compared to violet light.
• Which component deviates maximum?
• The violet colour has the minimum speed in prism, so the violet colour is deviated the maximum.
•
• Which component deviates minimum?
• The red colour has the maximum speed in prism, so the red colour is deviated the minimum.
•
• Rate of photosynthesis?
• Wavelength of the component that increases the rate of photosynthesis - 0.7 microns.
• The rate of photosynthesis is the most in the presence of red light.
•
• Which colour doesn’t affect the rate of photosynthesis?
• Component which does not affect the rate of photosynthesis - green light.
• The rate of photosynthesis is zero in the presence of green light.
•
• What is the nature of the spectrum emerging out of the first prism?
• Nature of the spectrum emerging out of the first prism - a band or spectrum of seven colours is obtained.
• The prism splits white light into seven colours.
•
• What is the nature of the spectrum emerging out of the second prism?
• Nature of the spectrum emerging out of the second prism – white light is obtained.
• The seven colours of the visible spectrum combine to form white light.
•
•