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प्रश्न
What are the seven colours seen in a rainbow?
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उत्तर
The seven colours seen in a rainbow are red, orange, yellow, green, blue, indigo and violet.
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संबंधित प्रश्न
State the cause of dispersion of white light passing through a glass prism. How did Newton show that white light of sun contains seven colours using two identical glass prisms. Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the focus of the first prism.
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
What will happen if another similar glass prism is placed upside down behind the first prism?
The seven colours in the spectrum of sunlight in order, are represented as :
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.
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
An object AB is placed in front of a convex lens as shown in fig. 4. Complete the ray diagram and obtain the image formed and state the nature of the image.
A wave has wavelength 50Å of name the wave.
What is the cause of the dispersion of white light through a glass prism? Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in an inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the faces of the prisms.
Match the Columns:
| Column ‘A’ | Column ‘B’ |
| The wavelength of red light | (a) 600 nm |
| (b) 700 nm | |
| (c) 500 nm |
Rainbow is a beautiful natural phenomenon. It is the combined effect of a natural three processes together produced by light. Write it into the circle.
Say TRUE or FALSE
After passing through a prism, white light splits into a band of seven colours
State the correct sequence (1-7) of colours in the spectrum formed by the prisms A and B, shown in the following figure.
What is Newton’s disc?
In dispersion, the color of light that will bend more is ______.
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.
The dispersive powers of flint glass and crown glass are 0.053 and 0.034, respectively and their mean refractive indices are 1.68 and 1.53 for white light. Calculate the angle of the flint glass prism required to form an achromatic combination with a crown glass prism of refracting angle 4°:
dispersive power of crown glass? Given that µv = 1.5230, µr = 1.5145
A ray of light is incident at 45° on an equilateral prism in the diagram below.
- Name the phenomenon exhibited by the ray of light when it enters and emerges out of the prism.
- State the cause of the above phenomenon mentioned by you.
