A Narrow Beam Pq of White Light is Passing Through a Glass Prism Abc as Shown in the Diagram. - Science

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A narrow beam PQ of white light is passing through a glass prism ABC as shown in the diagram.

Trace it on your answer sheet and show the path of the emergent beam as observed on the screen DE.

(i) Write the name and cause of the phenomenon observed.

(ii) Where else in nature is this phenomenon observed?

(iii) Based on this observation, state the conclusion which can be drawn about the constituents of white light.

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Solution

(i) Dispersion of light

Cause: The dispersion of white light occurs because colors of white light travel at different speeds through glass prism. Different colours undergo different deviations on passing through prism.

(ii) Rainbow is the example of dispersion of light observed in nature.

It is caused due to dispersion of sunlight by water droplets in the atmosphere. It always forms in the direction opposite to the sun.

(iii) White light is a mixture of seven colours. The sequence of colours given by the prism is Violet, Indigo, Blue, Green, Yellow, Orange and Red. VIBGYOR is the acronym for this sequence. The red light bends the least and violet light bends the most.

Concept: Dispersion of Light Through Prism and Formation of Spectrum
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2013-2014 (March) All India Set 3

RELATED QUESTIONS

Study the following figure in which a student has marked the angle of incidence (∠i), angle of refraction (∠r), angle of emergence (∠e), angle of prism (∠A) and the angle of deviation (∠D). The correctly marked angles are

(a) ∠A and ∠i

(b) ∠A, ∠i and ∠r

(c) ∠A, ∠i, ∠e and ∠D

(d) ∠A, ∠i, ∠r and ∠D


Study the following ray diagram:

In this diagram, the angle of incidence, the angle of emergence and the angle of deviation respectively have been represented by

(A) y, p, z

(B) x, q, z

(C) p, y, z

(D) p, z, y


 What will happen if another similar glass prism is placed upside down behind the first prism?


Which is refracted most by a prism : red light or violet light? Explain why?


The colour of white light which is deviated the maximum on passing through the glass prism is:
(a) blue
(b) indigo
(c) red
(d) orange


Which of the following colour of white light has the least wavelength?
(a) red
(b) orange
(c) violet
(d) blue


When white light passes through a prism, it ............


The speed of light in air or vacuum is


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In which of the following four diagrams is the correct path of a ray of light passing through a glass prism shown ?



In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray: 

(A) is parallel to the incident ray

(B) perpendicular to the incident ray

(C) is parallel to the refracted ray

(D) bends at an angle to the direction of incident ray


What do you understand by the term spectrum?

What do you mean by spectrum?

A wave has wavelength 50Å of name the wave.


A wave has wavelength 50Å of State its one use.


Name the waves of lowest wavelength.


A Beam of Blue, Green, and Yellow Light Passes Through The Earth's Atmosphere. Name the Colour Which is Scattered the Least.


The phenomenon of splitting of light into its component colours is ___________ .


Draw a labelled diagram: Dispersion of light through a prism.


Answer the following:

What do you mean by dispersion? Name the different colours of light in the proper sequence in the spectrum of light. 


How can the presence of infrared Radiations be detected?


Write the range of wavelength of the visible spectrum.


Write the range of wavelength of the ultraviolet spectrum.


Match the Columns:

Column ‘A’ Column ‘B’
The wavelength of red light (a) 600 nm
(b) 700 nm
(c) 500 nm

The process of separation of light into its component colours while passing through a medium is called _______.


Write an Explanation.

Critical angle


Draw a neat and labelled diagram for dispersion of light.


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Observe the given figure and write appropriate phenomenon of light in the box.


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  1. Which colour light rays bend most?
  2. Which colour light rays bend least.
  3. What is the wavelength of violet light rays?

The splitting of white light in to seven colors is called ______.


The sunlight can be split into its constituent colors using ______.


Say TRUE or FALSE

Rainbow is formed by dispersion of which light by water drops


Say TRUE or FALSE

After passing through a prism, white light splits into a band of seven colours


What is dispersion? Explain in detail.


Define dispersion of light.


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During dispersion of white light by prism placed in air, for a particular value of angle of prism,


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The angle of deviation through a prism is minimum when

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  3. The angle of incidence is equal to that of the angle of emergence.
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Choose the correct answer from the options given below:


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A prism of refractive index `sqrt2` and refracting angle A produces minimum deviation δm of a ray on one face at an angle of incidence 45°, The values of A and δm are, respectively ______.


State True or False:

"Wavelength of red light is close to 700 nm.”


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State the colour which bends:

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  1. Name the process shown in the figure.
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  3. Name the colour that deviates the least.
  4. Name any one phenomenon in nature which is based on the above process.
  5. Define ‘spectrum’.

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