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प्रश्न
Describe how you could demonstrate that white light is composed of a number of colours.
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उत्तर
We can show that white light is composed of a number of colours by passing it through a transparent glass prism. A glass prism is a triangular refracting surface. When a beam of white light enters the prism, the light splits, forming a band of seven colours on a screen placed on the other side of the prism. This splitting of light into its constituent colours is called dispersion of light. The formation of seven colours in a spectrum shows that white light is composed of these seven colours, namely, red, orange, yellow, green, blue, indigo and violet.
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संबंधित प्रश्न
Define the term dispersion of white light.
Draw a diagram to show the refraction of light through a glass prism. On this diagram, mark
(i) incident ray
(ii) emergent ray, and
(iii) angle of deviation.
The speed of light in air or vacuum is
Define the term dispersion of light.
Explain briefly, with the help of a neat labelled diagram, how white light gets dispersed by a prism. On which surface of a prism, there is both dispersion and deviation of light, and on which surface of the prism, there is only deviation of light ?
What conclusion do you draw about the nature of white light in part (b)?
When a white light ray falls on a prism, the ray at its first surface suffers ______.
In the spectrum of white light by a prism, the colour at the extreme end opposite to the base of prism is ______.
The frequency range of visible light is from 3.75 × 1014 Hz to 7.5 × 1014 Hz. Calculate its wavelength range. Take speed of light = 3 × 108 m/s.
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
A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so.
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 wavelength range of white light is ______.
Distinguish between an impure spectrum and a pure spectrum.
In the figure, a beam of light consisting of three colours blue, red, and yellow is incident on a prism and on a rectangular glass block respectively. Complete the diagram by drawings of the refracted and emergent rays.
Draw a neat and labelled diagram for dispersion of light.
Which of the following is a natural phenomenon which is caused by the dispersion of sunlight in the sky?
The phenomena of light involved in the formation of rainbow are ______.
Curved mirrors have surfaces that are spherical, cylindrical, parabolic, and ellipsoid.
Observe the given diagram and answer the questions:
- Name the process shown in the figure.
- Name the colour that deviates the most.
- Name the colour that deviates the least.
- Name any one phenomenon in nature which is based on the above process.
- Define ‘spectrum’.
