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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
Study the following diagrams in which the path of a ray of light passing through a glass prism as traced by four students P, Q, R and S is shown:
The student who has traced the path correctly is
(A) P
(B) Q
(C) R
(D) S
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
The path of a ray of light passing through a glass prism is shown below:
In this diagram, the angle of prism, angle of incidence, angle of emergence and angle of deviation, respectively, have been represented by:
(A) O, Y, Z and N,
(B) P, Y, M and Z,
(C) O, X, M and Z,
(D) P, X, Z and N.
As light rays pass from air into a glass prism, are they refracted towards or away from the normal?
How could you show that the colours of the spectrum combine to give white light?
Which of the following coloured light has the least speed in glass prism?
(a) violet
(b) yellow
(c) red
(d) green
Out of the following, the colour of light having the maximum wavelength is:
(a) violet
(b) indigo
(c) green
(d) orange
A ray of light moving from an optically rarer to a denser medium
When we place a glass prism in the path of a narrow beam of white light a spectrum is obtained. What happens when a second identical prism is placed in an inverted position with respect to the first prism? Draw a labelled ray diagram to illustrate it.
Make the correct choice for each of the following:
Which one of the following Fig correctly shows the path of the ray through the glass block?
What do you understand by spectrum? Name the seven prominent colours in order, as obtained in the spectrum of white light.
Write the range of wavelength of the infrared spectrum.
Match the Columns:
| Column ‘A’ | Column ‘B’ |
| The wavelength of red light | (a) 600 nm |
| (b) 700 nm | |
| (c) 500 nm |
Write an Explanation.
Critical angle
Observe the given figure and write appropriate phenomenon of light in the box.
Observe the given figure and answer the following questions.
- Which colour light rays bend most?
- Which colour light rays bend least.
- What is the wavelength of violet light rays?
Say TRUE or FALSE
After passing through a prism, white light splits into a band of seven colours
What is Newton’s disc?
The angle of deviation through a prism is minimum when
- Incident rays and emergent rays are symmetric to the prism.
- The refracted ray inside the prism becomes parallel to its base.
- The angle of incidence is equal to that of the angle of emergence.
- When the angle of emergence has doubled the angle of incidence.
Choose the correct answer from the options given below:
