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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 the 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.
संबंधित प्रश्न
Study the following ray diagram:
In this diagram, the angle of incidence, the angle of emergence and the angle of deviation respectively have been represented by
(A) y, p, z
(B) x, q, z
(C) p, y, z
(D) p, z, y
A beam of white light is shone onto a glass prism. The light cannot be:
(a) deviated
(b) dispersed
(c) focused
(d) refracted
Out of the following, the colour of light having the maximum wavelength is:
(a) violet
(b) indigo
(c) green
(d) orange
- 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)?
When a white light ray falls on a prism, the ray at its first surface suffers ______.
Sunlight entering through a narrow aperture falls on a prism. Draw a neat labelled ray diagram to show the formation of the spectrum on a screen. Name the colour obtained nearer the base of the prism.
In the diagram, a narrow beam of white light is incident on a right-angled isosceles prism. The critical angle of the material of prism for the yellow colour of white light is 45°. Complete the diagram to show the path of blue, yellow, and red colours of white light till they emerge out of the prism.
The periscope is an optical device with a polished surface that reflects the light falling on it.
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’.
