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प्रश्न
What is a rainbow?
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उत्तर
A rainbow is a curving optical phenomenon of seven colours caused by the refraction, reflection, and dispersion of sunlight in water droplets. The rainbow is seen as a large area in the sky with many colors.
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संबंधित प्रश्न
After tracing the path of a ray of light through a glass prism a student marked the angle of incidence (∠i), angle of refraction (∠r) angle of emergence (∠e) and the angle of deviation (∠D) as shown in the diagram. The correctly marked angles are :

(A) ∠i and ∠r
(B) ∠i and ∠e
(C) ∠i, ∠e and ∠D
(D) ∠i, ∠r and ∠e
Draw a ray diagram to explain the term angle of deviation.
In the formation of spectrum of white light by a prism:
which colour is deviated least?
What do you understand by the term spectrum? Name the various colours present in the spectrum of sunlight.
- A beam of monochromatic light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
- If white light is used in the same way as in part (a) above, what change do you expect in the emergent beam?
- What conclusion do you draw about the nature of white light in part (b)?
Refer to fig
(i) Name the lens L.
(ii) What are the points O, O' called?
(iii) Complete the diagram to form the image of the object AB.
(iv) Write three characteristics of the image.

The wavelengths of violet and red light are 4000 Å and 8000 Å respectively. Which of the two has the higher frequency?
A student has to trace the path of a ray of light through a glass prism. List four precautions he should observe for better results.
Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.
State the correct sequence (1-7) of colours in the spectrum formed by the prisms A and B, shown in the following figure.

