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प्रश्न
What is a rainbow? What are the two conditions necessary for the formation of a rainbow in the sky?
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उत्तर
A rainbow is a natural spectrum of seven colours formed in the sky when the water droplets in the atmosphere cause the dispersion of sunlight. The two conditions necessary for the formation of a rainbow are as follows.
1. The sun should be shining.
2. It should be raining.
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संबंधित प्रश्न
In the following ray diagram the correctly marked angle are:
(a) ∠i and ∠e
(b) ∠A and ∠D
(c) ∠i, ∠e and ∠D
(d) ∠r, ∠A and ∠D
Describe how you could demonstrate that white light is composed of a number of colours.
The colour of white light which suffers the maximum bending (or maximum refraction) on passing through a glass prism is:
(a) yellow
(b) orange
(c) red
(d) violet
Which of the following colour of white light has the least wavelength?
(a) red
(b) orange
(c) violet
(d) blue
The diagram below shows the path taken by a narrow beam of yellow monochromatic light passing through an equiangular glass prism. If the yellow light is replaced by a narrow beam of white light incident at the same angle, draw another diagram to show the passage of white light through the prism and label it to show the effect of prism on the white light.
- 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)?
In an experiment to trace the path of a ray of light through a triangular glass prism, a student would observe that the emergent ray
(a) is parallel to the incident ray.
(b) is along the same direction of incident ray.
(c) gets deviated and bends towards the thinner part of the prism.
(d) gets deviated and bends towards the thicker part (base) of the prism.
While performing the experiment to trace the path of a ray of light passing through a glass prism, four students marked the incident ray and the emergent ray in their diagrams in the manner shown below. 
(A) I
(B) II
(C) III
(D) IV
Complete the ray diagram given below to show the nature of light produced on the screen.
The completed ray diagram is as shown below:
An object is placed in front of a converging lens and in front of a diverging lens as in fig.
(a)Complete the ray diagram to obtain an image.
(b)Compare the nature of image formed by both the lenses in the above case.
Differentiate between a glass slab and a glass prism.
Which characteristic property of light is responsible for the blue colour of the sky?
What do you understand by spectrum? Name the seven prominent colours in order, as obtained in the spectrum of white light.
Suggest one way, in each case, by which we can detect the presence of Infrared radiations.
The splitting of white light in to seven colors is called ______.
The splitting of white light into its component colours is called ____________.
Curved mirrors have surfaces that are spherical, cylindrical, parabolic, and ellipsoid.
Assertion: We can see the rainbow in the sky when the rain starts falling after a spell of bright sunlight.
Reason: The rainbow is formed due to the dispersion of light.
During dispersion of white light by prism placed in air, for a particular value of angle of prism,
